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  • CLASSES

    Miscellaneous Antidepressants

    BOXED WARNING

    Children, suicidal ideation

    Safety and efficacy of vilazodone have not been establishedin children or adolescents under 18 years of age. Vilazodone has been studied in adolescent patients with major depressive disorder (MDD) in a multicenter phase 3 trial, but efficacy was not confirmed, although the safety and tolerability of the drug in these patients appeared similar to adult patients. In a pooled analysis of placebo-controlled trials of antidepressants (n = 4,500 pediatrics and 77,000 adults), there was an increased risk for suicidal thoughts and behaviors in patients 24 years of age and younger receiving an antidepressant versus placebo, with considerable variation in the risk of suicidality among drugs. The difference in absolute risk of suicidal thoughts and behaviors across different indications was highest in those with major depression. No suicides occurred in any of the pediatric trials. Nevertheless, the need for an antidepressant in children, adolescents, or young adults for any use must be weighed against the risk of suicidality; it is unknown if this risk extends to long-term use. All patients should be monitored for symptom worsening or suicidality, especially at treatment initiation or after dose changes. Caregivers and/or patients should immediately notify the prescriber of changes in behavior or suicidal ideation. A change to the treatment regimen or discontinuation of vilazodone may be necessary in patients with emerging suicidality or worsening depression.

    DEA CLASS

    Rx

    DESCRIPTION

    Oral antidepressant that modulates serotonin; a dual selective serotonin reuptake inhibitor and partial serotonin 5-HT1A agonist
    Used for the treatment of major depressive disorder in adults
    Increased risk of suicidality during the initial stages of treatment in pediatric and young adult patients

    COMMON BRAND NAMES

    VIIBRYD

    HOW SUPPLIED

    VIIBRYD Oral Tab: 10mg, 20mg, 40mg, 10-20mg

    DOSAGE & INDICATIONS

    For the treatment of major depression.
    Oral dosage
    Adults

    10 mg PO once daily with food for 7 days, then 20 mg once daily with food for 7 days.  After that, may increase after a minimum of 7 days between dosage increases. The target dose is 20 to 40 mg PO once daily with food. Max: 40 mg/day PO. Coadministration of certain drugs may need to be avoided or dosage adjustments may be necessary; review drug interactions. Periodically reassess the need for continued treatment. Guidance on the appropriate length of treatment is available through the American Psychiatric Association treatment guidelines for patients with major depressive disorder.

    MAXIMUM DOSAGE

    Adults

    40 mg/day PO.

    Geriatric

    40 mg/day PO.

    Adolescents

    Safety and efficacy have not been established.

    Children

    Safety and efficacy have not been established.

    Infants

    Safety and efficacy have not been established.

    Neonates

    Safety and efficacy have not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    No dosage adjustments are recommended in patients with mild, moderate, or severe hepatic impairment.

    Renal Impairment

    Mild to severe renal Impairment, estimated GFR 15 to 90 mL/minute: No dosage adjustments are necessary.

    ADMINISTRATION

    Oral Administration
    Oral Solid Formulations

    Administer vilazodone tablets with food. Administration without food may decrease effectiveness.

    STORAGE

    VIIBRYD:
    - Store at 77 degrees F; excursions permitted to 59-86 degrees F

    CONTRAINDICATIONS / PRECAUTIONS

    General Information

    Although not specifically noted in the prescribing label, use vilazodone with caution in patients reporting hypersensitivity to the drug. Advise patients to notify their healthcare provider if they develop a potential allergic reaction such as rash, hives, swelling, or difficulty breathing.

    MAOI therapy

    Vilazodone is contraindicated in patients taking monoamine oxidase inhibitors (MAOI therapy), including MAOIs such as linezolid or intravenous methylene blue, because of an increased risk of serotonin syndrome. Vilazodone should not be given within 14 days of stopping an MAOI.

    Children, suicidal ideation

    Safety and efficacy of vilazodone have not been establishedin children or adolescents under 18 years of age. Vilazodone has been studied in adolescent patients with major depressive disorder (MDD) in a multicenter phase 3 trial, but efficacy was not confirmed, although the safety and tolerability of the drug in these patients appeared similar to adult patients. In a pooled analysis of placebo-controlled trials of antidepressants (n = 4,500 pediatrics and 77,000 adults), there was an increased risk for suicidal thoughts and behaviors in patients 24 years of age and younger receiving an antidepressant versus placebo, with considerable variation in the risk of suicidality among drugs. The difference in absolute risk of suicidal thoughts and behaviors across different indications was highest in those with major depression. No suicides occurred in any of the pediatric trials. Nevertheless, the need for an antidepressant in children, adolescents, or young adults for any use must be weighed against the risk of suicidality; it is unknown if this risk extends to long-term use. All patients should be monitored for symptom worsening or suicidality, especially at treatment initiation or after dose changes. Caregivers and/or patients should immediately notify the prescriber of changes in behavior or suicidal ideation. A change to the treatment regimen or discontinuation of vilazodone may be necessary in patients with emerging suicidality or worsening depression.

    Bipolar disorder, mania

    Carefully monitor all patients for emotional lability, worsening of symptoms, or unusual behaviors during vilazodone treatment. Vilazodone should be used cautiously in patients with a history of bipolar disorder (mania or hypomania) because it is possible that treatment with an antidepressant alone may increase the likelihood of precipitation of a mixed/manic episode in patients at risk for bipolar disorder. It should be noted that vilazodone is not approved for use in treating bipolar depression. Patients should be adequately screened for bipolar disorder prior to initiating an antidepressant. Such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder, and depression. If a patient develops manic symptoms, vilazodone should be withheld and appropriate therapy initiated to treat the mania. All patients with depression or comorbid depression in the setting of other psychiatric illness being treated with antidepressants should be observed for clinical worsening and suicidality, especially during the initial few months of a course of drug therapy, or at times of dose changes. Patients and caregivers should be advised to communicate immediately with the prescriber the emergence of agitation, irritability, unusual changes in behavior, or suicidality.

    Seizure disorder, seizures

    Vilazodone has not been formally evaluated in those with a history of seizures or a seizure disorder; patients with a history of seizures were excluded from premarketing clinical trials. Use caution when administering the drug to these patient populations.

    Anticoagulant therapy, bleeding, thrombolytic therapy

    Monitor patients taking vilazodone for signs and symptoms of bleeding. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage). Concurrent use of aspirin, NSAIDs, anticoagulant therapy, thrombolytic therapy, or other medications that enhance bleeding potential may increase this risk. Patients taking vilazodone should be instructed to promptly report any bleeding events to the practitioner.

    Dehydration, hyponatremia, hypovolemia

    Hyponatremia has been associated with the use of medications that inhibit serotonin reuptake, including vilazodone. In some instances, serum sodium levels less than 110 mmol/L have occurred; however, the adverse effect appeared reversible upon discontinuation of the causative agent. Older adult patients (65 years of age and older), those receiving diuretics or prone to dehydration, and those who are otherwise volume depleted (e.g., hypovolemia) appear to be at greatest risk. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of the causative agent, as well as implementation of the appropriate medical interventions.

    Closed-angle glaucoma, increased intraocular pressure

    Avoid use of antidepressants, including vilazodone, in patients with untreated closed-angle glaucoma. The pupillary dilation that occurs following use of many antidepressant drugs, including vilazodone, may trigger an angle-closure attack in a patient with anatomically narrow angles who does not have a patent iridectomy. An acute attack of closed-angle glaucoma is considered a medical emergency because the increased intraocular pressure is rapid and severe, and may quickly result in blindness if left untreated.

    Abrupt discontinuation

    Discontinuation symptoms have been reported during abrupt discontinuation of serotonergic drugs such as vilazodone; therefore, avoid sudden discontinuation whenever possible. It is recommended that vilazodone be tapered gradually. The product label offers some guidance for tapering the dosage. For example, taper a 40 mg/day dose down to 20 mg/day for 4 days, followed by 10 mg/day for 3 days, then discontinue. Taper a 20 mg/day dose down to 10 mg/day for 7 days, then discontinue. Patients should be monitored for symptoms of withdrawal when discontinuing treatment.

    Driving or operating machinery, ethanol ingestion

    Because psychoactive drugs such as vilazodone may impair judgment, thinking, or motor skills, patients should avoid tasks requiring mental alertness such as driving or operating machinery or other hazardous activities until they know how the drug affects them. Patients should generally avoid ethanol ingestion while taking vilazodone.

    Sexual dysfunction

    Sexual dysfunction can occur in individuals taking vilazodone. For males, these effects may present as ejaculatory failure or delay, decreased libido, and/or erectile dysfunction. Females may experience decreased libido and delayed or absent orgasm. Prescribers should discuss sexual function prior to initiating treatment with vilazodone and throughout treatment and obtain a detailed history and timeline of any changes in sexual function to determine whether the changes are medication-related or may be attributed to the underlying psychiatric disorder. Clinicians should also discuss management strategies and treatment options with patients.

    Labor, neonates, obstetric delivery, pregnancy

    There are no adequate studies to determine safety of vilazodone use during pregnancy in humans; therefore, the drug should be used during pregnancy only when the benefit to the mother clearly outweighs any potential risk to the fetus. Because there is some evidence indicating that women who discontinue antidepressants during pregnancy may be more likely to experience a relapse of major depression than women who continued antidepressants during pregnancy, the manufacturer recommends considering the risks of untreated depression when discontinuing or changing antidepressant treatment during pregnancy and postpartum. Neonates exposed to serotonergic antidepressants, including vilazodone, late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. Such complications can arise immediately upon delivery. Findings have included respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability, and constant crying. Features are consistent with either a direct toxic effect of serotonergic agents or, possibly, a neonatal abstinence syndrome. It should be noted that, in some cases, the clinical picture is consistent with serotonin syndrome. Additionally, epidemiologic reports suggest an association between maternal use of SSRIs after 20 weeks gestation and the development of persistent pulmonary hypertension of the newborn (PPHN). More recent retrospective studies have not shown an increased risk of PPHN with SSRI exposure. In December 2011, the FDA issued a safety announcement stating that based on conflicting data an increased risk of PPHN from SSRI exposure cannot be determined. The FDA advises that healthcare professionals should not alter their current practice of treating depression in pregnancy at this time. When treating a pregnant woman with vilazodone during the third trimester, the physician should carefully consider the potential risks and benefits of treatment. There are no adequate studies to determine safety of vilazodone use during labor or delivery. If clinically feasible, gradual tapering of the medication prior to obstetric delivery may be considered. There is a pregnancy exposure registry that monitors outcomes in pregnant patients exposed to vilazodone; information about the registry can be obtained at womensmentalhealth.org/clinical-and-research-programs/pregnancyregistry/antidepressants or by calling 1-866-961-2388 or 1-844-405-6185.

    Breast-feeding

    There are no published clinical data regarding the use of vilazodone during lactation and breast-feeding. According to the manufacturer, vilazodone should only be considered for use during breast-feeding if the potential benefit to the mother outweighs the potential risk to the infant, taking into account the clinical need of the mother and any potential adverse effects on the breastfed child from vilazodone or from the underlying maternal condition. Consider alternative agents due to the lack of clinical data.A pooled analysis found that maternal use of sertraline, along with nortriptyline and paroxetine, usually produced undetectable or low drug concentrations in infant serum and, therefore, may be the preferred antidepressants in breast-feeding mothers. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.

    Geriatric

    Clinical studies for vilazodone did not include sufficient numbers of older adults 65 years of age and older to determine whether they respond differently from younger adults. Geriatric adults have an increased risk of developing clinically significant hyponatremia, a known side effect of serotonin-enhancing antidepressants. However, no other differences in side effects were noted based on age. Vilazodone was not reviewed at the time of the last Beers Criteria publication. The federal Omnibus Budget Reconciliation Act (OBRA) regulates the use of antidepressants in residents of long-term care facilities; the duration of therapy is determined by pertinent literature and clinical practice guidelines for the condition being treated. Monitor closely for worsening of depression and suicidal behavior or thinking, especially during initiation of therapy and during dose changes. Monitor for side effects of the antidepressant; some of these effects can increase the risk of falls. Review for continued need of the antidepressant at least quarterly and document the rationale for continuation. When the drug is being used to manage behavior, stabilize mood, or treat a psychiatric disorder, the facility should attempt to taper the medication as outlined in the OBRA guidelines, unless a taper is clinically contraindicated. Before discontinuation, many antidepressants, including vilazodone, need a taper to avoid a withdrawal/discontinuation syndrome.

    ADVERSE REACTIONS

    Severe

    serotonin syndrome / Delayed / 0.1-0.1
    suicidal ideation / Delayed / Incidence not known
    pancreatitis / Delayed / Incidence not known
    ocular hypertension / Delayed / Incidence not known
    GI bleeding / Delayed / Incidence not known
    SIADH / Delayed / Incidence not known
    seizures / Delayed / Incidence not known
    neonatal abstinence syndrome / Early / Incidence not known
    persistent pulmonary hypertension of the newborn / Delayed / Incidence not known

    Moderate

    palpitations / Early / 2.0-2.0
    ejaculation dysfunction / Delayed / 2.0-2.0
    impotence (erectile dysfunction) / Delayed / 2.0-2.0
    blurred vision / Early / 0.1-1.0
    mania / Early / 0.1-0.1
    cataracts / Delayed / 0-0.1
    migraine / Early / 1.0
    hallucinations / Early / Incidence not known
    sleep paralysis / Delayed / Incidence not known
    akathisia / Delayed / Incidence not known
    depression / Delayed / Incidence not known
    hematoma / Early / Incidence not known
    platelet dysfunction / Delayed / Incidence not known
    bleeding / Early / Incidence not known
    hyponatremia / Delayed / Incidence not known
    withdrawal / Early / Incidence not known

    Mild

    diarrhea / Early / 28.0-28.0
    nausea / Early / 23.0-23.0
    headache / Early / 14.0-15.0
    dizziness / Early / 9.0-9.0
    xerostomia / Early / 8.0-8.0
    insomnia / Early / 6.0-6.0
    vomiting / Early / 5.0-5.0
    libido decrease / Delayed / 3.0-5.0
    fatigue / Early / 4.0-4.0
    orgasm dysfunction / Delayed / 2.0-4.0
    paresthesias / Delayed / 3.0-3.0
    restlessness / Early / 2.0-3.0
    drowsiness / Early / 3.0-3.0
    abnormal dreams / Early / 2.0-3.0
    dyspepsia / Early / 3.0-3.0
    flatulence / Early / 3.0-3.0
    arthralgia / Delayed / 3.0-3.0
    tremor / Early / 2.0-2.0
    appetite stimulation / Delayed / 2.0-2.0
    anxiety / Delayed / 0.1-1.0
    dysgeusia / Early / 0.1-1.0
    night sweats / Early / 0.1-1.0
    hyperhidrosis / Delayed / 0.1-1.0
    xerophthalmia / Early / 0.1-1.0
    anorexia / Delayed / 1.0
    restless legs syndrome (RLS) / Delayed / Incidence not known
    irritability / Delayed / Incidence not known
    urticaria / Rapid / Incidence not known
    rash / Early / Incidence not known
    petechiae / Delayed / Incidence not known
    ecchymosis / Delayed / Incidence not known
    epistaxis / Delayed / Incidence not known

    DRUG INTERACTIONS

    Abciximab: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Acetaminophen; Caffeine; Dihydrocodeine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering dihydrocodeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Acetaminophen; Caffeine; Magnesium Salicylate; Phenyltoloxamine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction. (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Acetaminophen; Caffeine; Phenyltoloxamine; Salicylamide: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction. (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Acetaminophen; Chlorpheniramine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Acetaminophen; Chlorpheniramine; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Acetaminophen; Chlorpheniramine; Phenylephrine; Phenyltoloxamine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Acetaminophen; Codeine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering codeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Acetaminophen; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Acetaminophen; Dextromethorphan; Doxylamine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Acetaminophen; Dextromethorphan; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Acetaminophen; Dichloralphenazone; Isometheptene: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics.
    Acetaminophen; Diphenhydramine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Acetaminophen; Hydrocodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Acetaminophen; Oxycodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering oxycodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Acetaminophen; Pamabrom; Pyrilamine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Acetaminophen; Pentazocine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering pentazocine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Acetaminophen; Propoxyphene: (Moderate) Coadministration of propoxyphene and vilazodone increases the risk for CNS depression and serotonin syndrome. Carefully monitor the patient and discontinue treatment if serotonin syndrome is suspected.
    Acrivastine; Pseudoephedrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Alfentanil: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering alifentanil with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Alprazolam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Alteplase: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving thrombolytic agents. Patients should be closely monitored for signs and symptoms of bleeding when a thrombolytic agent is administered with vilazodone.
    Amiloride: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Aminosalicylate sodium, Aminosalicylic acid: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Amlodipine; Celecoxib: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Amoxicillin; Clarithromycin; Omeprazole: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as clarithromycin. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Amphetamines: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and vilazodone. At high doses, amphetamines can increase serotonin release and act as serotonin agonists. Monitor for the emergence of serotonin syndrome particularly after a dose increase or the addition of other serotonergic medications. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
    Anagrelide: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Anticoagulants: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Antithrombin III: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Anxiolytics; Sedatives; and Hypnotics: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics.
    Apalutamide: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with apalutamide is necessary for more than 14 days. After discontinuation of apalutamide, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and apalutamide is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Apixaban: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Argatroban: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Aspirin, ASA: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Butalbital; Caffeine: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Butalbital; Caffeine; Codeine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering codeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Caffeine: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Caffeine; Dihydrocodeine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering dihydrocodeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Caffeine; Orphenadrine: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Carisoprodol: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Carisoprodol; Codeine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering codeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Dipyridamole: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Omeprazole: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Oxycodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering oxycodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Aspirin, ASA; Pravastatin: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Atazanavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as atazanavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Atazanavir; Cobicistat: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as atazanavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued. (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with cobicistat is necessary; the original dose of vilazodone can be resumed if cobicistat is discontinued. Vilazodone is a CYP3A4 substrate and cobicistat is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Atenolol; Chlorthalidone: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Atropine; Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Contraindicated) According to the manufacturer of vilazodone, treatment initiation with vilazodone is contraindicated in patients currently receiving intravenous (IV) methylene blue due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than vilazodone (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients requiring urgent treatment with IV methylene blue, vilazodone should be discontinued immediately and methylene blue therapy initiated only if acceptable alternatives are not available and the potential benefits outweigh the risks. The patient should be monitored for serotonin syndrome for 2 weeks or until 24 hours after the last dose of methylene blue, whichever comes first. Vilazodone may be re-initiated 24 hours after the last dose of methylene blue. Methylene blue is a thiazine dye that is also a potent, reversible inhibitor of the enzyme responsible for the catabolism of serotonin in the brain (MAO-A) and vilazodone is a selective serotonin reuptake inhibitor and partial 5-HT1 agonist. Concurrent use of an MAO-A inhibitor with a serotonergic agent may result in a clinically significant interaction. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving serotonin-augmenting agents. It is not known if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between IV methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Serotonin syndrome is characterized by rapid development of various symptoms such as hyperthermia, hypertension, myoclonus, rigidity, hyperhidrosis, incoordination, diarrhea, mental status changes (e.g., confusion, delirium, or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Azilsartan; Chlorthalidone: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Belladonna Alkaloids; Ergotamine; Phenobarbital: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as ergot alkaloids (e.g., ergotamine or dihydroergotamine). Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an ergot alkaloid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the ergot alkaloid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated. (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with phenobarbital is necessary for more than 14 days. After discontinuation of phenobarbital, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and phenobarbital is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Belladonna; Opium: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering opium with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Bendroflumethiazide; Nadolol: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Benzhydrocodone; Acetaminophen: (Moderate) Concomitant use of benzhydrocodone with vilazodone may cause sedation, somnolence, and increased risk of serotonin syndrome. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome.
    Benzodiazepines: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Contraindicated) According to the manufacturer of vilazodone, treatment initiation with vilazodone is contraindicated in patients currently receiving intravenous (IV) methylene blue due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than vilazodone (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients requiring urgent treatment with IV methylene blue, vilazodone should be discontinued immediately and methylene blue therapy initiated only if acceptable alternatives are not available and the potential benefits outweigh the risks. The patient should be monitored for serotonin syndrome for 2 weeks or until 24 hours after the last dose of methylene blue, whichever comes first. Vilazodone may be re-initiated 24 hours after the last dose of methylene blue. Methylene blue is a thiazine dye that is also a potent, reversible inhibitor of the enzyme responsible for the catabolism of serotonin in the brain (MAO-A) and vilazodone is a selective serotonin reuptake inhibitor and partial 5-HT1 agonist. Concurrent use of an MAO-A inhibitor with a serotonergic agent may result in a clinically significant interaction. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving serotonin-augmenting agents. It is not known if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between IV methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Serotonin syndrome is characterized by rapid development of various symptoms such as hyperthermia, hypertension, myoclonus, rigidity, hyperhidrosis, incoordination, diarrhea, mental status changes (e.g., confusion, delirium, or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Betrixaban: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Bismuth Subsalicylate: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Bivalirudin: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Boceprevir: (Major) CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone and boceprevir is a strong CYP3A4 inhibitor. Concurrent use of vilazodone and boceprevir may lead to an increased risk of vilazodone-related adverse reactions. The manufacturer recommends a reduction in vilazodone dose to 20 mg/day in patients receiving a strong CYP3A4 inhibitor. When the inhibitor is discontinued, resume the previous vilazodone dose.
    Brompheniramine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Brompheniramine; Carbetapentane; Phenylephrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Brompheniramine; Dextromethorphan; Guaifenesin: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Brompheniramine; Guaifenesin; Hydrocodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Brompheniramine; Hydrocodone; Pseudoephedrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Brompheniramine; Phenylephrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Brompheniramine; Pseudoephedrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Bumetanide: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Bupivacaine; Meloxicam: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Buprenorphine: (Moderate) Concomitant use of buprenorphine with vilazodone may cause sedation, somnolence, and increased risk of serotonin syndrome. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Buprenorphine; Naloxone: (Moderate) Concomitant use of buprenorphine with vilazodone may cause sedation, somnolence, and increased risk of serotonin syndrome. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Buspirone: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as buspirone. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and buspirone should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and buspirone should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Butalbital; Acetaminophen; Caffeine; Codeine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering codeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Butorphanol: (Moderate) Because of the potential risk and severity of CNS depression, respiratory depression, and serotonin syndrome, caution should be observed when administering butorphanol with vilazodone. Inform patients taking this combination of the possible increased risks and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Carbamazepine: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with carbamazepine is necessary for more than 14 days. After discontinuation of carbamazepine, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and carbamazepine is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Carbetapentane; Chlorpheniramine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Carbetapentane; Chlorpheniramine; Phenylephrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Carbetapentane; Diphenhydramine; Phenylephrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Carbetapentane; Phenylephrine; Pyrilamine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Carbetapentane; Pyrilamine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Carbinoxamine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Carbinoxamine; Dextromethorphan; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Carbinoxamine; Hydrocodone; Phenylephrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Carbinoxamine; Hydrocodone; Pseudoephedrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Carbinoxamine; Phenylephrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Carbinoxamine; Pseudoephedrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Celecoxib: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Celecoxib; Tramadol: (Moderate) Because of the potential risk and severity of CNS effects and serotonin syndrome, caution should be observed when administering tramadol with vilazodone. Inform patients taking this combination of the possible increased risks and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Ceritinib: (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with ceritinib is necessary; the original dose of vilazodone can be resumed if ceritinib is discontinued. Vilazodone is a CYP3A4 substrate and ceritinib is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Chlophedianol; Dexbrompheniramine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chloral Hydrate: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics.
    Chloramphenicol: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as chloramphenicol. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Chlorcyclizine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlordiazepoxide: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Chlordiazepoxide; Amitriptyline: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Chlordiazepoxide; Clidinium: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Chlorothiazide: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Chlorpheniramine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Codeine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering codeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering dihydrocodeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Dihydrocodeine; Pseudoephedrine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering dihydrocodeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Guaifenesin; Hydrocodone; Pseudoephedrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Hydrocodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Hydrocodone; Phenylephrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Hydrocodone; Pseudoephedrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction. (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Chlorpheniramine; Phenylephrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorpheniramine; Pseudoephedrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Chlorthalidone: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Chlorthalidone; Clonidine: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Choline Salicylate; Magnesium Salicylate: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Cilostazol: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Citalopram: (Major) Due to the potential for serotonin syndrome, caution is advisable when combining selective serotonin reuptake inhibitors (SSRIs) such as citalopram with vilazodone. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and citalopram should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. If serotonin syndrome occurs, all serotonergic agents should be discontinued and supportive symptomatic treatment should be initiated.
    Clarithromycin: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as clarithromycin. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Clemastine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Clonazepam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Clopidogrel: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Clorazepate: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Cobicistat: (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with cobicistat is necessary; the original dose of vilazodone can be resumed if cobicistat is discontinued. Vilazodone is a CYP3A4 substrate and cobicistat is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Cocaine: (Major) Because of the potential risk and severity of serotonin syndrome or neuroleptic malignant syndrome-like reactions, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as cocaine. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. Patients receiving this combination should be monitored closely for toxicity.
    Codeine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering codeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Codeine; Guaifenesin: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering codeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Codeine; Guaifenesin; Pseudoephedrine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering codeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Codeine; Phenylephrine; Promethazine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering codeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Codeine; Promethazine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering codeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Cyclizine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Cyclobenzaprine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as cyclobenzaprine. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. Patients receiving this combination should be monitored closely for toxicity. Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as cyclobenzaprine. Patients should be advised to avoid driving or engaging in other tasks requiring mental alertness until they know how this combination affects them.
    Cyproheptadine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Dabigatran: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Dalteparin: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Danaparoid: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Darunavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as darunavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Darunavir; Cobicistat: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as darunavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued. (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with cobicistat is necessary; the original dose of vilazodone can be resumed if cobicistat is discontinued. Vilazodone is a CYP3A4 substrate and cobicistat is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as darunavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued. (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with cobicistat is necessary; the original dose of vilazodone can be resumed if cobicistat is discontinued. Vilazodone is a CYP3A4 substrate and cobicistat is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as ritonavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Delavirdine: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as delavirdine. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Desirudin: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Dexbrompheniramine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Dexbrompheniramine; Pseudoephedrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Dexchlorpheniramine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Dextromethorphan; Guaifenesin: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Dextromethorphan; Guaifenesin; Potassium Guaiacolsulfonate: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Dextromethorphan; Quinidine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Diazepam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Diclofenac: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Diclofenac; Misoprostol: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Diflunisal: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Digoxin: (Moderate) Concomitant use of digoxin, a P-gp substrate, and vilazodone may increase digoxin concentrations. Because digoxin is a narrow therapeutic index drug, serum digoxin concentrations should be measured before initiating vilazodone, with periodic monitoring throughout concurrent treatment. Adjust the digoxin dose as necessary.
    Dihydrocodeine; Guaifenesin; Pseudoephedrine: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering dihydrocodeine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Dihydroergotamine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as ergot alkaloids (e.g., ergotamine or dihydroergotamine). Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an ergot alkaloid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the ergot alkaloid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Dimenhydrinate: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Diphenhydramine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Diphenhydramine; Hydrocodone; Phenylephrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Diphenhydramine; Ibuprofen: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction. (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Diphenhydramine; Naproxen: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction. (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Diphenhydramine; Phenylephrine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Dipyridamole: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Dolasetron: (Major) Because of the potential risk and severity of serotonin syndrome, use caution when administering dolasetron with other drugs that have serotonergic properties such as vilazodone. If serotonin syndrome is suspected, discontinue dolasetron and concurrent serotonergic agents and initiate appropriate medical treatment. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death.
    Doxylamine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Doxylamine; Pyridoxine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Dronabinol: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as dronabinol, THC.
    Droperidol: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics.
    Edoxaban: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Elbasvir; Grazoprevir: (Minor) Administering vilazodone with grazoprevir may result in elevated vilazodone plasma concentrations. Vilazodone is a substrate of CYP3A; grazoprevir is a weak CYP3A inhibitor. If these drugs are used together, closely monitor for signs of adverse events.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with cobicistat is necessary; the original dose of vilazodone can be resumed if cobicistat is discontinued. Vilazodone is a CYP3A4 substrate and cobicistat is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with cobicistat is necessary; the original dose of vilazodone can be resumed if cobicistat is discontinued. Vilazodone is a CYP3A4 substrate and cobicistat is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Enoxaparin: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Enzalutamide: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with enzalutamide is necessary for more than 14 days. After discontinuation of enzalutamide, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and enzalutamide is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Eptifibatide: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Ergoloid Mesylates: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as ergot alkaloids (e.g., ergotamine or dihydroergotamine). Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an ergot alkaloid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the ergot alkaloid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Ergonovine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as ergot alkaloids (e.g., ergotamine or dihydroergotamine). Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an ergot alkaloid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the ergot alkaloid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Ergot alkaloids: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as ergot alkaloids (e.g., ergotamine or dihydroergotamine). Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an ergot alkaloid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the ergot alkaloid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Ergotamine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as ergot alkaloids (e.g., ergotamine or dihydroergotamine). Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an ergot alkaloid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the ergot alkaloid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Ergotamine; Caffeine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as ergot alkaloids (e.g., ergotamine or dihydroergotamine). Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an ergot alkaloid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the ergot alkaloid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Escitalopram: (Major) Due to possible additive effects on serotonin concentrations, it is advisable to avoid combining selective serotonin reuptake inhibitors (SSRIs), such as escitalopram, with vilazodone. Interactions between serotonergic agents can lead to serotonin syndrome. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and escitalopram should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and escitalopram should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Estazolam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Eszopiclone: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics.
    Ethacrynic Acid: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Ethanol: (Moderate) Patients should be advised to avoid alcohol consumption during treatment with vilazodone to avoid additive CNS depressant effects. (Moderate) Patients should be advised to avoid ethanol consumption during treatment with vilazodone to avoid additive CNS depressant effects.
    Etodolac: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Famotidine; Ibuprofen: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Fenfluramine: (Moderate) Use fenfluramine and vilazodone with caution due to an increased risk of serotonin syndrome. Monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Fenoprofen: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Fentanyl: (Moderate) Because of the potential risk and severity of excessive sedation, respiratory depression, and serotonin syndrome, caution should be observed when administering fentanyl with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Use a lower initial dose of the opiate and titrate to clinical response. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Fluoxetine: (Major) Due to possible additive effects on serotonin concentrations, it is advisable to avoid combining selective serotonin reuptake inhibitors (SSRIs) with vilazodone. Interactions between vilazodone and serotonergic agents can lead to serious reactions including serotonin syndrome. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving this combination should be monitored closely for toxicity.
    Flurazepam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Flurbiprofen: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Fluvoxamine: (Major) Due to possible additive effects on serotonin concentrations, it is advisable to avoid combining selective serotonin reuptake inhibitors (SSRIs) with vilazodone. Interactions between vilazodone and serotonergic agents can lead to serious reactions including serotonin syndrome. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving this combination should be monitored closely for toxicity. In addition, because vilazodone is a primary CYP3A4 substrate, the manufacturer recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as fluvoxamine. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Fondaparinux: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Fosamprenavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as fosamprenavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Fosphenytoin: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with fosphenytoin is necessary for more than 14 days. After discontinuation of fosphenytoin, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and fosphenytoin is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Furosemide: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Granisetron: (Major) Because of the potential risk and severity of serotonin syndrome, use caution when administering granisetron with other drugs that have serotonergic properties such as vilazodone. If serotonin syndrome is suspected, discontinue granisetron and concurrent serotonergic agents and initiate appropriate medical treatment. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death.
    Guaifenesin; Hydrocodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Guaifenesin; Hydrocodone; Pseudoephedrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Heparin: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Homatropine; Hydrocodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Hydralazine; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Hydrocodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Hydrocodone; Ibuprofen: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Hydrocodone; Phenylephrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Hydrocodone; Potassium Guaiacolsulfonate: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Hydrocodone; Potassium Guaiacolsulfonate; Pseudoephedrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Hydrocodone; Pseudoephedrine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydrocodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Hydromorphone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering hydromorphone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Hydroxyzine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Contraindicated) According to the manufacturer of vilazodone, treatment initiation with vilazodone is contraindicated in patients currently receiving intravenous (IV) methylene blue due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than vilazodone (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients requiring urgent treatment with IV methylene blue, vilazodone should be discontinued immediately and methylene blue therapy initiated only if acceptable alternatives are not available and the potential benefits outweigh the risks. The patient should be monitored for serotonin syndrome for 2 weeks or until 24 hours after the last dose of methylene blue, whichever comes first. Vilazodone may be re-initiated 24 hours after the last dose of methylene blue. Methylene blue is a thiazine dye that is also a potent, reversible inhibitor of the enzyme responsible for the catabolism of serotonin in the brain (MAO-A) and vilazodone is a selective serotonin reuptake inhibitor and partial 5-HT1 agonist. Concurrent use of an MAO-A inhibitor with a serotonergic agent may result in a clinically significant interaction. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving serotonin-augmenting agents. It is not known if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between IV methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Serotonin syndrome is characterized by rapid development of various symptoms such as hyperthermia, hypertension, myoclonus, rigidity, hyperhidrosis, incoordination, diarrhea, mental status changes (e.g., confusion, delirium, or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Ibuprofen: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Ibuprofen; Oxycodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering oxycodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Ibuprofen; Pseudoephedrine: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Idelalisib: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as idelalisib. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Indinavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as indinavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Indomethacin: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Irbesartan; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Isocarboxazid: (Contraindicated) Due to the risk of serotonin syndrome, monoamine oxidase inhibitors (MAOIs) intended to treat psychiatric disorders, such as isocarboxazid, are contraindicated for use with vilazodone or within 14 days of discontinuing treatment with vilazodone. Conversely, vilazodone should not be initiated within 14 days of stopping an MAOI.
    Isoniazid, INH: (Major) Due to the risk of serotonin syndrome, concurrent use of vilazodone and medications with MAO-like activity, such as isoniazid, INH should be avoided if possible. Isoniazid is chemically related to iproniazid, a drug that was known to possess MAO inhibiting activity. Although isoniazid does not inhibit mitochondrial MAO, it does appear to inhibit plasma MAO and may possess enough MAO inhibiting activity to produce clinical symptoms consistent with serotonergic excess when combined with selective serotonin reuptake inhibitors. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death.
    Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Major) Due to the risk of serotonin syndrome, concurrent use of vilazodone and medications with MAO-like activity, such as isoniazid, INH should be avoided if possible. Isoniazid is chemically related to iproniazid, a drug that was known to possess MAO inhibiting activity. Although isoniazid does not inhibit mitochondrial MAO, it does appear to inhibit plasma MAO and may possess enough MAO inhibiting activity to produce clinical symptoms consistent with serotonergic excess when combined with selective serotonin reuptake inhibitors. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with rifampin is necessary for more than 14 days. After discontinuation of rifampin, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and rifampin is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Isoniazid, INH; Rifampin: (Major) Due to the risk of serotonin syndrome, concurrent use of vilazodone and medications with MAO-like activity, such as isoniazid, INH should be avoided if possible. Isoniazid is chemically related to iproniazid, a drug that was known to possess MAO inhibiting activity. Although isoniazid does not inhibit mitochondrial MAO, it does appear to inhibit plasma MAO and may possess enough MAO inhibiting activity to produce clinical symptoms consistent with serotonergic excess when combined with selective serotonin reuptake inhibitors. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with rifampin is necessary for more than 14 days. After discontinuation of rifampin, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and rifampin is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Itraconazole: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as itraconazole. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Ketoconazole: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as ketoconazole. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Ketoprofen: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Ketorolac: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Lansoprazole; Amoxicillin; Clarithromycin: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as clarithromycin. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Lansoprazole; Naproxen: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Lasmiditan: (Moderate) Serotonin syndrome may occur during coadministration of lasmiditan and vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome, particularly after a dose increase or the addition of other serotonergic medications to an existing regimen. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
    Lepirudin: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Letermovir: (Moderate) Administering letermovir with vilazodone may increase vilazodone concentration. Do not exceed a vilazodone dose of 20 mg daily in patients who are also receiving cyclosporine, because the magnitude of this interaction may be increased. The original vilazodone dose may be resumed if letermovir or cyclosporine is discontinued. Vilazodone is primarily metabolized by CYP3A4. Letermovir is a moderate CYP3A4 inhibitor; however, when given with cyclosporine, the combined effect may be similar to a strong CYP3A4 inhibitor.
    Levoketoconazole: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as ketoconazole. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Levorphanol: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering levorphanol with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Linezolid: (Contraindicated) According to the manufacturer of vilazodone, treatment initiation with vilazodone is contraindicated in patients currently receiving linezolid due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than vilazodone (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients receiving vilazodone and requiring urgent treatment with linezolid, vilazodone should be discontinued immediately and linezolid therapy initiated only if acceptable alternatives are not available and the potential benefits of linezolid outweigh the risks. The patient should be monitored for serotonin syndrome for two weeks or until 24 hours after the last dose of linezolid, whichever comes first. Vilazodone may be re-initiated 24 hours after the last dose of linezolid. Linezolid is an antibiotic that is also a non-selective monoamine oxidase (MAO) inhibitor. Since monoamine oxidase type A deaminates serotonin, administration of a non-selective MAO inhibitor concurrently with vilazodone can lead to serotonin syndrome. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death.
    Lisinopril; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Lithium: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as lithium. Lithium has been reported to increase 5-hydroxytryptamine metabolites in the cerebrospinal fluid and may interact pharmacodynamically with serotonergic agents resulting in serotonin syndrome. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and lithium should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and lithium should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Lonafarnib: (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with lonafarnib is necessary; the original dose of vilazodone can be resumed if lonafarnib is discontinued. Vilazodone is a CYP3A4 substrate and lonafarnib is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Loop diuretics: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Lopinavir; Ritonavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as ritonavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Lorazepam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Losartan; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Lumacaftor; Ivacaftor: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with lumacaftor; ivacaftor is necessary for more than 14 days. After discontinuation of lumacaftor; ivacaftor, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and lumacaftor; ivacaftor is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Magnesium Salicylate: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Meclizine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Meclofenamate Sodium: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Mefenamic Acid: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Meloxicam: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Meperidine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering meperidine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Meperidine; Promethazine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering meperidine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Meprobamate: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics.
    Methadone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering methadone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Methenamine; Sodium Acid Phosphate; Methylene Blue; Hyoscyamine: (Contraindicated) According to the manufacturer of vilazodone, treatment initiation with vilazodone is contraindicated in patients currently receiving intravenous (IV) methylene blue due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than vilazodone (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients requiring urgent treatment with IV methylene blue, vilazodone should be discontinued immediately and methylene blue therapy initiated only if acceptable alternatives are not available and the potential benefits outweigh the risks. The patient should be monitored for serotonin syndrome for 2 weeks or until 24 hours after the last dose of methylene blue, whichever comes first. Vilazodone may be re-initiated 24 hours after the last dose of methylene blue. Methylene blue is a thiazine dye that is also a potent, reversible inhibitor of the enzyme responsible for the catabolism of serotonin in the brain (MAO-A) and vilazodone is a selective serotonin reuptake inhibitor and partial 5-HT1 agonist. Concurrent use of an MAO-A inhibitor with a serotonergic agent may result in a clinically significant interaction. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving serotonin-augmenting agents. It is not known if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between IV methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Serotonin syndrome is characterized by rapid development of various symptoms such as hyperthermia, hypertension, myoclonus, rigidity, hyperhidrosis, incoordination, diarrhea, mental status changes (e.g., confusion, delirium, or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
    Methyclothiazide: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Methylene Blue: (Contraindicated) According to the manufacturer of vilazodone, treatment initiation with vilazodone is contraindicated in patients currently receiving intravenous (IV) methylene blue due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than vilazodone (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients requiring urgent treatment with IV methylene blue, vilazodone should be discontinued immediately and methylene blue therapy initiated only if acceptable alternatives are not available and the potential benefits outweigh the risks. The patient should be monitored for serotonin syndrome for 2 weeks or until 24 hours after the last dose of methylene blue, whichever comes first. Vilazodone may be re-initiated 24 hours after the last dose of methylene blue. Methylene blue is a thiazine dye that is also a potent, reversible inhibitor of the enzyme responsible for the catabolism of serotonin in the brain (MAO-A) and vilazodone is a selective serotonin reuptake inhibitor and partial 5-HT1 agonist. Concurrent use of an MAO-A inhibitor with a serotonergic agent may result in a clinically significant interaction. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving serotonin-augmenting agents. It is not known if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between IV methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Serotonin syndrome is characterized by rapid development of various symptoms such as hyperthermia, hypertension, myoclonus, rigidity, hyperhidrosis, incoordination, diarrhea, mental status changes (e.g., confusion, delirium, or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
    Methylergonovine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as ergot alkaloids (e.g., ergotamine or dihydroergotamine). Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an ergot alkaloid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the ergot alkaloid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Methylphenidate Derivatives: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when coadministering drugs that have serotonergic properties such as methylphenidate derivatives and vilazodone. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving this combination should be monitored closely for toxicity. If serotonin syndrome occurs, all serotonergic agents should be discontinued and appropriate medical management should be implemented.
    Methysergide: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as ergot alkaloids (e.g., ergotamine or dihydroergotamine). Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an ergot alkaloid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the ergot alkaloid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Metolazone: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Metoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Midazolam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Mirabegron: (Minor) Mirabegron is a moderate CYP2D6 inhibitor. Exposure of drugs metabolized by CYP2D6 isoenzymes such as vilazodone may be increased when co-administered with mirabegron. However, CYP2D6 is a minor metabolic pathway for vilazodone. Appropriate monitoring may be necessary.
    Mirtazapine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as mirtazapine. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. Patients receiving this combination should be monitored for toxicity. Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as mirtazapine.
    Mitotane: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with mitotane is necessary for more than 14 days. After discontinuation of mitotane, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and mitotane is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Morphine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering morphine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Morphine; Naltrexone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering morphine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Nabilone: (Moderate) Nabilone should be combined cautiously with many antidepressants, such as vilazodone, as drowsiness or other CNS effects may occur.
    Nabumetone: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Nalbuphine: (Moderate) Because of the potential risk and severity of CNS depression and serotonin syndrome, caution should be observed when administering nalbuphine with vilazodone. Inform patients taking this combination of the possible increased risks and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Naproxen: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Naproxen; Esomeprazole: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Naproxen; Pseudoephedrine: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Nefazodone: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as nefazodone. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. In addition, CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, and nefazodone is a strong inhibitor of CYP3A4. The manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Nelfinavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as nelfinavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Netupitant, Fosnetupitant; Palonosetron: (Major) Because of the potential risk and severity of serotonin syndrome, use caution and monitor closely when administering palonosetron with other drugs that have serotonergic properties, such as vilazodone. If serotonin syndrome is suspected, discontinue palonosetron and concurrent serotonergic agents and initiate appropriate medical treatment. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. (Moderate) Netupitant is a moderate inhibitor of CYP3A4 and should be used with caution in patients receiving concomitant medications that are primarily metabolized through CYP3A4, such as vilazodone. The plasma concentrations of vilazodone can increase when co-administered with netupitant; the inhibitory effect on CYP3A4 can last for multiple days. The manufacturer of vilazodone recommends a reduction in vilazodone dose to 20 mg/day in patients receiving a moderate CYP3A4 inhibitor who are experiencing intolerable side effects. When the inhibitor is discontinued, resume the previous vilazodone dose.
    Nirmatrelvir; Ritonavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as ritonavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Nonsteroidal antiinflammatory drugs: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Olanzapine; Fluoxetine: (Major) Due to possible additive effects on serotonin concentrations, it is advisable to avoid combining selective serotonin reuptake inhibitors (SSRIs) with vilazodone. Interactions between vilazodone and serotonergic agents can lead to serious reactions including serotonin syndrome. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving this combination should be monitored closely for toxicity.
    Oliceridine: (Moderate) If concomitant use of oliceridine and vilazodone is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
    Olmesartan; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Olmesartan; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Ombitasvir; Paritaprevir; Ritonavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as ritonavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Ondansetron: (Major) Because of the potential risk and severity of serotonin syndrome, use caution when administering ondansetron with other drugs that have serotonergic properties such as vilazodone. If serotonin syndrome is suspected, discontinue ondansetron and concurrent serotonergic agents and initiate appropriate medical treatment. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death.
    Oxaprozin: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Oxazepam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Oxycodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering oxycodone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Oxymorphone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering oxymorphone with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Ozanimod: (Major) Coadministration of ozanimod with vilazodone is not recommended due to the potential for hypertensive crisis and serotonin syndrome. If coadministration is necessary, closely monitor patients for hypertension and serotonergic effects. An active metabolite of ozanimod inhibits MAO-B, which may increase the potential for hypertensive crisis and serotonin syndrome. Vilazodone may increase blood pressure or cause serotonergic side effects by increasing serotonin concentrations.
    Palonosetron: (Major) Because of the potential risk and severity of serotonin syndrome, use caution and monitor closely when administering palonosetron with other drugs that have serotonergic properties, such as vilazodone. If serotonin syndrome is suspected, discontinue palonosetron and concurrent serotonergic agents and initiate appropriate medical treatment. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death.
    Paroxetine: (Major) Due to possible additive effects on serotonin concentrations, it is advisable to avoid combining selective serotonin reuptake inhibitors (SSRIs) such as paroxetine with vilazodone. Interactions between vilazodone and serotonergic agents can lead to serotonin syndrome. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and paroxetine should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and paroxetine should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Pentazocine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering pentazocine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Pentazocine; Naloxone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering pentazocine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Pentosan: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Pergolide: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as ergot alkaloids (e.g., ergotamine or dihydroergotamine). Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an ergot alkaloid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the ergot alkaloid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Phenelzine: (Contraindicated) Due to the risk of serotonin syndrome, monoamine oxidase inhibitors (MAOIs) intended to treat psychiatric disorders, such as phenelzine, are contraindicated for use with vilazodone or within 14 days of discontinuing treatment with vilazodone. Conversely, vilazodone should not be initiated within 14 days of stopping an MAOI.
    Phenobarbital: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with phenobarbital is necessary for more than 14 days. After discontinuation of phenobarbital, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and phenobarbital is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with phenobarbital is necessary for more than 14 days. After discontinuation of phenobarbital, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and phenobarbital is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Phentermine: (Moderate) Use phentermine and vilazodone together with caution; use together might be efficacious for some patients based on available data, provided the patient is on a stable antidepressant regimen and receives close clinical monitoring. Regular appointments to assess the efficacy of the weight loss treatment, the emergence of adverse events, and blood pressure monitoring are recommended. Watch for excessive serotonergic effects. Phentermine is related to the amphetamines, and there has been historical concern that phentermine might exhibit potential to cause serotonin syndrome or cardiovascular or pulmonary effects when combined with serotonergic agents. One case report describes adverse reactions with phentermine and the antidepressant fluoxetine. However, recent data suggest that phentermine's effect on MAO inhibition and serotonin augmentation is minimal at therapeutic doses, and that phentermine does not additionally increase plasma serotonin levels when combined with other serotonergic agents. In large controlled clinical studies, patients were allowed to start therapy with extended-release phentermine or extended-release phentermine combinations for obesity along with their antidepressants (e.g., SSRIs or SNRIs, but not MAOIs or TCAs) as long as the antidepressant dose had been stable for at least 3 months prior to the initiation of phentermine, and the patient did not have suicidal ideation or more than 1 episode of major depression documented. In analyses of the results, therapy was generally well tolerated, especially at lower phentermine doses, based on discontinuation rates and reported adverse events. Because depression and obesity often coexist, the study data may be important to providing optimal therapies.
    Phentermine; Topiramate: (Moderate) Use phentermine and vilazodone together with caution; use together might be efficacious for some patients based on available data, provided the patient is on a stable antidepressant regimen and receives close clinical monitoring. Regular appointments to assess the efficacy of the weight loss treatment, the emergence of adverse events, and blood pressure monitoring are recommended. Watch for excessive serotonergic effects. Phentermine is related to the amphetamines, and there has been historical concern that phentermine might exhibit potential to cause serotonin syndrome or cardiovascular or pulmonary effects when combined with serotonergic agents. One case report describes adverse reactions with phentermine and the antidepressant fluoxetine. However, recent data suggest that phentermine's effect on MAO inhibition and serotonin augmentation is minimal at therapeutic doses, and that phentermine does not additionally increase plasma serotonin levels when combined with other serotonergic agents. In large controlled clinical studies, patients were allowed to start therapy with extended-release phentermine or extended-release phentermine combinations for obesity along with their antidepressants (e.g., SSRIs or SNRIs, but not MAOIs or TCAs) as long as the antidepressant dose had been stable for at least 3 months prior to the initiation of phentermine, and the patient did not have suicidal ideation or more than 1 episode of major depression documented. In analyses of the results, therapy was generally well tolerated, especially at lower phentermine doses, based on discontinuation rates and reported adverse events. Because depression and obesity often coexist, the study data may be important to providing optimal therapies.
    Phenytoin: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with phenytoin is necessary for more than 14 days. After discontinuation of phenytoin, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and phenytoin is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Piroxicam: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Platelet Inhibitors: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Posaconazole: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as posaconazole. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Potassium-sparing diuretics: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Prasugrel: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Primidone: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with primidone is necessary for more than 14 days. After discontinuation of primidone, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and primidone is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Procarbazine: (Major) Due to the risk of serotonin syndrome, concurrent use of vilazodone and medications with MAO-like activity, such as procarbazine, should be avoided if possible. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
    Promethazine; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with vilazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Propoxyphene: (Moderate) Coadministration of propoxyphene and vilazodone increases the risk for CNS depression and serotonin syndrome. Carefully monitor the patient and discontinue treatment if serotonin syndrome is suspected.
    Propranolol; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Pseudoephedrine; Triprolidine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Pyrilamine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Quazepam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Quinapril; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Ramelteon: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics.
    Rasagiline: (Major) Avoid concurrent use of rasagiline and antidepressants such as vilazodone if possible. Serotonin syndrome has been reported during concurrent use of antidepressants and selective or non-selective MAOIs. During post-marketing use of rasagiline, non-fatal cases of serotonin syndrome have been reported during concomitant antidepressant use. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
    Remifentanil: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering remifentanil with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Remimazolam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Reteplase, r-PA: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving thrombolytic agents. Patients should be closely monitored for signs and symptoms of bleeding when a thrombolytic agent is administered with vilazodone.
    Ribociclib: (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with ribociclib is necessary; the original dose of vilazodone can be resumed if ribociclib is discontinued. Vilazodone is a CYP3A4 substrate and ribociclib is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Ribociclib; Letrozole: (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with ribociclib is necessary; the original dose of vilazodone can be resumed if ribociclib is discontinued. Vilazodone is a CYP3A4 substrate and ribociclib is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Rifampin: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with rifampin is necessary for more than 14 days. After discontinuation of rifampin, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and rifampin is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Rifapentine: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with rifapentine is necessary for more than 14 days. After discontinuation of rifapentine, resume the previous vilazodone dose over 1 to 2 weeks. Vilazodone is primarily metabolized by CYP3A4 and rifapentine is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Ritonavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as ritonavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Rivaroxaban: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Rofecoxib: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Safinamide: (Contraindicated) Concurrent use of vilazodone and safinamide, a monoamine oxidase inhibitor (MAOI), or use of vilazodone within 2 weeks of stopping safinamide is contraindicated due to the risk of serotonin syndrome. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death.
    Salicylates: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Salsalate: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Saquinavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as saquinavir boosted with ritonavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Sedating H1-blockers: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Selegiline: (Contraindicated) Vilazodone is contraindicated for use with selegiline, a selective monoamine oxidase type B inhibitor (MAO-B inhibitor). At least 14 days should elapse between discontinuation of selegiline and initiation of treatment with vilazodone. After stopping treatment with vilazodone, a time period equal to 4 to 5 half-lives of vilazodone or any active metabolite should elapse before starting therapy with selegiline. Serotonin syndrome has occurred in patients receiving selective MAO-B inhibitors and serotonergic antidepressants simultaneously.
    Serotonin norepinephrine reuptake inhibitors: (Major) Due to possible additive effects on serotonin concentrations, it is advisable to avoid combining serotonin norepinephrine reuptake inhibitors (SNRIs) with vilazodone. Interactions between vilazodone and serotonergic agents can lead to serotonin syndrome. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and an SNRI should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the SNRI should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Serotonin-Receptor Agonists: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as serotonin-receptor agonists (e.g., almotriptan, eletriptan, frovatriptan, naratriptan, rizatriptan, sumatriptan, zolmitriptan). Serotonin syndrome has been reported during concurrent use of serotonin norepinephrine reuptake inhibitors (SNRIs) or selective serotonin reuptake inhibitors (SSRIs) with serotonin-receptor agonists. Of the 27 cases reviewed by the FDA, 2 were considered life-threatening and 13 required hospitalization. Some patients had used the combination previously without incident. Eight of 27 cases involved a recent dose increase or addition of another serotonergic drug to the regimen, with a median onset of 1 day (range: 10 minutes to 6 days). It is thought that the interaction between SNRIs or SSRIs and serotonin-receptor agonists is the result of increased serotonergic activity by each of the drug classes. Serotonin syndrome consists of symptoms such as mental status changes (e.g., agitation, confusion, hallucinations), diaphoresis, hyperreflexia, hypertension, diarrhea, fever, tremor, and, in some instances, respiratory failure. At least 6 patients taking an SSRI antidepressant are known to have received sumatriptan for migraine where no apparent adverse effects were seen. In another case report, the addition of fluoxetine lead to loss of migraine control with sumatriptan. Patients receiving vilazodone and a serotonin-receptor agonist should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the serotonin-receptor agonist should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Sertraline: (Major) Due to possible additive effects on serotonin concentrations, it is advisable to avoid combining selective serotonin reuptake inhibitors (SSRIs) with vilazodone. Interactions between vilazodone and serotonergic agents can lead to serotonin syndrome. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and sertraline should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and sertraline should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Sibutramine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vilazodone with other drugs that have serotonergic properties such as sibutramine. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and sibutramine should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and sibutramine should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Spironolactone: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Spironolactone; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    St. John's Wort, Hypericum perforatum: (Moderate) Consider increasing the dose of vilazodone up to 2-fold over 1 to 2 weeks (maximum, 80 mg per day) based on clinical response if coadministration with St. John's Wort is necessary for more than 14 days. After discontinuation of St. John's Wort, resume the previous vilazodone dose over 1 to 2 weeks. Also, inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. Vilazodone is primarily metabolized by CYP3A4 and St. John's Wort is a strong CYP3A4 inducer. Decreased plasma concentrations of vilazodone are expected if vilazodone is used concomitantly with strong CYP3A4 inducers.
    Streptokinase: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving thrombolytic agents. Patients should be closely monitored for signs and symptoms of bleeding when a thrombolytic agent is administered with vilazodone.
    Sufentanil: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering sufentanil with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Sulindac: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Sumatriptan; Naproxen: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Tapentadol: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering tapentadol with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Tedizolid: (Major) Caution is warranted with the concurrent use of tedizolid and vilazodone due to the theoretical risk of serotonin sydrome. Animal studies did not predict serontoneric effects with tedizolid; however, patients on concurrent SNRIs were excluded from clinical trials. Addtionally, tedizolid is an antibiotic that is also a weak reversible, non-selective MAO inhibitor and monoamine oxidase type A deaminates serotonin; therefore, coadministration theoretically could lead to serious reactions including serotonin syndrome. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and tedizolid should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and tedizolid should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Telaprevir: (Major) CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone and telaprevir is a strong CYP3A4 inhibitor. Concurrent use of vilazodone and telaprevir may lead to an increased risk of vilazodone-related adverse reactions. The manufacturer recommends a reduction in vilazodone dose to 20 mg/day in patients receiving a strong CYP3A4 inhibitor. When the inhibitor is discontinued, resume the previous vilazodone dose.
    Telithromycin: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as telithromycin. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Telmisartan; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Temazepam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Tenecteplase: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving thrombolytic agents. Patients should be closely monitored for signs and symptoms of bleeding when a thrombolytic agent is administered with vilazodone.
    Thiazide diuretics: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Thioridazine: (Major) Although the manufacturer of vilazodone states that co-administration of vilazodone (a moderate CYP2D6 inhibitor) with most CYP2D6 substrates is unlikely to result in clinically significant concentration changes, caution is advisable during concurrent use of thioridazine with vilazodone. Thioridazine is a CYP2D6 substrate with an established risk of QT prolongation and torsade de pointes. Elevated concentrations of thioridazine can lead to QT prolongation, ventricular arrhythmias, and sudden death.
    Thrombolytic Agents: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving thrombolytic agents. Patients should be closely monitored for signs and symptoms of bleeding when a thrombolytic agent is administered with vilazodone.
    Ticagrelor: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Ticlopidine: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Tinzaparin: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Tipranavir: (Major) Because CYP3A4 is the primary isoenzyme involved in the metabolism of vilazodone, the manufacturer of vilazodone recommends that the daily dose not exceed 20 mg/day during concurrent use of a strong CYP3A4 inhibitor, such as tipranavir. The original vilazodone dose can be resumed when the CYP3A4 inhibitor is discontinued.
    Tirofiban: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Tolmetin: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Torsemide: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Tramadol: (Moderate) Because of the potential risk and severity of CNS effects and serotonin syndrome, caution should be observed when administering tramadol with vilazodone. Inform patients taking this combination of the possible increased risks and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Tramadol; Acetaminophen: (Moderate) Because of the potential risk and severity of CNS effects and serotonin syndrome, caution should be observed when administering tramadol with vilazodone. Inform patients taking this combination of the possible increased risks and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
    Tranylcypromine: (Contraindicated) Due to the risk of serotonin syndrome, monoamine oxidase inhibitors (MAOIs) intended to treat psychiatric disorders, such as tranylcypromine, are contraindicated for use with vilazodone or within 14 days of discontinuing treatment with vilazodone. Conversely, vilazodone should not be initiated within 14 days of stopping an MAOI.
    Trazodone: (Moderate) Vilazodone and trazodone have similar pharmacologic effects and may increase risk for sedation and serotonin syndrome. Serotonin syndrome has been reported with both drugs when taken alone, but especially when coadministered with other serotonergic agents. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome. Discontinue vilazodone and trazodone and initiate symptomatic treatment if serotonin syndrome occurs.
    Triamterene: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Triamterene; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Triazolam: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as the benzodiazepines.
    Tricyclic antidepressants: (Major) Vilazodone and Tricyclic antidepressants (TCAs) may cause additive CNS depression, including dizziness or drowsiness. These drugs can represent duplicate therapies and are not commonly prescribed together. In addition, because of the potential risk and severity of serotonin syndrome, caution should be observed. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and a TCA should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the TCA should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Triprolidine: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
    Tryptophan, 5-Hydroxytryptophan: (Major) Since tryptophan is converted to serotonin (5-hydroxytryptamine), the use of tryptophan in patients receiving vilazodone could lead to serotonin syndrome. This combination is not recommended. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
    Tucatinib: (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with tucatinib is necessary; the original dose of vilazodone can be resumed if tucatinib is discontinued. Vilazodone is a CYP3A4 substrate and tucatinib is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Urokinase: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving thrombolytic agents. Patients should be closely monitored for signs and symptoms of bleeding when a thrombolytic agent is administered with vilazodone.
    Valdecoxib: (Moderate) Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving nonsteroidal antiinflammatory drugs (NSAIDs). Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with NSAIDs and to promptly report any bleeding events to the practitioner.
    Valerian, Valeriana officinalis: (Moderate) Substances that act on the CNS, including psychoactive drugs and drugs used as anesthetic adjuvants, may theoretically interact with valerian, Valeriana officinalis. These interactions are probably pharmacodynamic in nature, or result from additive mechanisms of action. Patients taking medications such as vilazodone should discuss the use of herbal supplements with their health care professional prior to consuming these herbs. Patients should not abruptly stop taking their prescribed psychoactive medication.
    Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Patients receiving vilazodone with medications known to cause hyponatremia, such as diuretics, may be at increased risk of developing hyponatremia. Hyponatremia has occurred in association with the use of antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Symptomatic hyponatremia may require discontinuation of vilazodone, as well as implementation of the appropriate medical interventions.
    Vorapaxar: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with salicylates or other platelet inhibitors and to promptly report any bleeding events to the practitioner. Platelet aggregation may be impaired by vilazodone due to platelet serotonin depletion, possibly increasing the risk of a bleeding complication (e.g., gastrointestinal bleeding, ecchymoses, epistaxis, hematomas, petechiae, hemorrhage) in patients receiving platelet inhibitors (e.g., aspirin, cilostazol, clopidogrel, dipyridamole, ticlopidine, platelet glycoprotein IIb/IIIa inhibitors).
    Voriconazole: (Major) Do not exceed a vilazodone dose of 20 mg once daily if coadministration with voriconazole is necessary; the original dose of vilazodone can be resumed if voriconazole is discontinued. Vilazodone is a CYP3A4 substrate and voriconazole is a strong CYP3A4 inhibitor. Coadministration with another strong CYP3A4 inhibitor increased vilazodone exposure by 50%.
    Vortioxetine: (Major) Due to similarity of pharmacology and the potential for additive adverse effects, including serotonin syndrome, vortioxetine should generally not be administered with vilazodone. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome is suspected, vortioxetine and concurrent serotonergic agents should be discontinued.
    Warfarin: (Moderate) Patients should be instructed to monitor for signs and symptoms of bleeding while taking vilazodone concurrently with anticoagulants and to promptly report any bleeding events to the practitioner. Serotonergic agents may increase the risk of bleeding when combined with anticoagulants via inhibition of serotonin uptake by platelets; however, the absolute risk is not known. In addition, both vilazodone and warfarin are highly protein bound, which may result in displacement of warfarin from protein binding sites and an increased anticoagulant effect. It would be prudent for clinicians to monitor the INR and clinical status of the patient closely if vilazodone is added to or removed from the regimen of a patient stabilized on warfarin.
    Zaleplon: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics.
    Zolpidem: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics.

    PREGNANCY AND LACTATION

    Pregnancy

    There are no published clinical data regarding the use of vilazodone during lactation and breast-feeding. According to the manufacturer, vilazodone should only be considered for use during breast-feeding if the potential benefit to the mother outweighs the potential risk to the infant, taking into account the clinical need of the mother and any potential adverse effects on the breastfed child from vilazodone or from the underlying maternal condition. Consider alternative agents due to the lack of clinical data.A pooled analysis found that maternal use of sertraline, along with nortriptyline and paroxetine, usually produced undetectable or low drug concentrations in infant serum and, therefore, may be the preferred antidepressants in breast-feeding mothers. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.

    MECHANISM OF ACTION

    Vilazodone is a dual selective serotonin reuptake inhibitor and partial serotonin 5-HT1A agonist. Vilazodone does not exhibit a high binding affinity for norepinephrine or dopamine reuptake sites. Generally, the therapeutic effect of serotonin reuptake inhibitors is believed to occur via blockade of the reuptake of serotonin at the presynaptic neuronal membrane. Chronic exposure to increased serotonin levels in the CNS downregulates postsynaptic neuronal receptor binding sites. Because of the delay in therapeutic response to antidepressants, it is theorized that the change in the balance of serotonin receptors over time is an important mechanism of effect.

    PHARMACOKINETICS

    Vilazodone is administered orally. The therapeutic effect of the drug is primarily due to the parent compound. Steady-state is achieved in about 3 days. Vilazodone is widely distributed and is highly protein bound (approximately 96% to 99%). Vilazodone is extensively metabolized and metabolism includes CYP and non-CYP pathways (possibly by carboxylesterase). CYP3A4 is the primary isoenzyme involved. CYP2C19 and CYP2D6 are minor metabolic pathways. The half-life is about 25 hours. Unchanged vilazodone accounts for 1% and 2% of a dose excreted in urine and feces, respectively.
     
    Affected cytochrome P450 isoenzymes and drug transporters: CYP3A4, P-glycoprotein (P-gp)
    Vilazodone is predominantly metabolized by CYP3A4 and concurrent use of strong CYP3A4 inhibitors may result in a 50% increase in vilazodone plasma concentrations. Likewise, co-administration of strong CYP3A4 inducers can decrease systemic exposure of the drug by approximately 45%. Concurrent use of vilazodone and CYP2C19 or CYP2D6 inhibitors is not expected to alter vilazodone plasma concentrations. In vitro studies indicate that vilazodone is unlikely to inhibit or induce the metabolism of substrates for CYP1A1, 1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, 3A4 or 3A5, except for CYP2C8. The effect of vilazodone on CYP2C8 activity has not been tested in vivo. Based on pharmacokinetic studies, no dosage adjustment is required for drugs that are substrates of CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A4, and/or P-glycoprotein (except narrow therapeutic index drugs, e.g., digoxin), when vilazodone is administered concomitantly. Vilazodone appears to inhibit P-gp.

    Oral Route

    Following oral administration, peak vilazodone concentrations occur at a median of 4 to 5 hours. The absolute bioavailability of vilazodone when administered with food is 72%. Plasma concentrations may be decreased by 50% when administered orally in a fasting state compared to a fed state with the potential for a decrease in efficacy. Therefore, administration of vilazodone with food is recommended. Absorption is reduced by about 25% if vomiting occurs within 7 hours of ingestion; however, no replacement dose is needed if this occurs.