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  • CLASSES

    Anticonvulsants, Benzodiazepines
    Anxiolytics, Benzodiazepines

    BOXED WARNING

    Asthma, bronchitis, chronic obstructive pulmonary disease (COPD), CNS depression, coadministration with other CNS depressants, coma, pulmonary disease, respiratory depression, shock, sleep apnea

    As with other benzodiazepines, clonazepam should be used with extreme caution in patients with pulmonary disease or conditions associated with compromised respiratory function such as sleep apnea, bronchitis, pneumonia, asthma, or chronic obstructive pulmonary disease (COPD). Additionally, avoid coadministration with other CNS depressants, especially opioids, unless no other alternatives are available as coadministration significantly increases the risk for respiratory depression, low blood pressure, and death. If coadministration is necessary, follow patients for signs and symptoms of respiratory depression and sedation. Clonazepam should not be used in patients with preexisting respiratory depression, cases of shock, or coma because the drug can worsen respiratory and CNS depression. In patients who snore regularly, partial airway obstruction may convert to obstructive sleep apnea with benzodiazepine administration. Clonazepam may produce hypersalivation and may aggravate conditions in which patients have difficulty handling secretions.

    DEA CLASS

    Rx, schedule IV

    DESCRIPTION

    Oral long-acting benzodiazepine
    Noticeable efficacy in the treatment of absence, petit mal variant (Lennox-Gastaut syndrome), and akinetic and myoclonic seizures, but ineffective for tonic-clonic seizures
    Also used for panic disorder and restless leg syndrome.

    COMMON BRAND NAMES

    Ceberclon, Klonopin

    HOW SUPPLIED

    Ceberclon/Clonazepam/Klonopin Oral Tab: 0.5mg, 1mg, 2mg
    Clonazepam/Klonopin Oral Tab Orally Dis: 0.125mg, 0.25mg, 0.5mg, 1mg, 2mg

    DOSAGE & INDICATIONS

    For the alternative treatment of absence seizures, petit mal variant (Lennox-Gastaut syndrome), and akinetic and myoclonic seizures (myoclonia).
    Oral dosage
    Adults and Adolescents (weight > 30 kg)

    Initially, 1.5 mg/day PO, divided into 3 equal doses. This dosage may be increased by 0.5 to 1 mg every 3 days until seizures are controlled. Maximum dosage of 20 mg/day PO. The typical maintenance dose range is 2 to 8 mg/day.

    Geriatric and Debilitated Adult patients

    See adult dosage; may require lower initial dosages and/or slower dosage titration.

    Infants and Children <= 10 years (weight <= 30 kg)

    Initially, 0.01 to 0.03 mg/kg/day PO (not to exceed 0.05 mg/kg/day), given in 3 equally divided doses. Increase dosage by not more than 0.25 to 0.5 mg every 3rd day to a maximum maintenance dosage of 0.1 to 0.2 mg/kg/day PO administered in 3 divided doses until seizures are controlled or adverse reactions limit further increase. Whenever possible, the daily dose should be divided into 3 equal doses. If doses are not equally divided, the largest dose should be given before retiring.

    For the treatment of panic disorder with or without agoraphobia.
    Oral dosage
    Adults

    0.25 mg PO twice daily initially, increasing to 1 mg/day after 3 days in most patients. Higher doses per day are associated with more adverse effects. However, some individual patients may benefit from titration, and in those instances, may increase by 0.125 to 0.25 mg twice daily every 3 days until panic disorder is controlled or until intolerance occurs. Max: 4 mg/day PO. If discontinuation becomes necessary, gradually decrease by 0.125 mg twice daily every 3 days.

    Geriatric Adults

    Initiate treatment with a low adult dose and monitor closely. The elderly may be more sensitive to the effects of benzodiazepines. The initial dose in younger adults is 0.25 mg PO twice daily, increasing to 1 mg/day after 3 days in most patients. Some individual patients may benefit from higher doses, and in those instances, the dose may be increased in increments of 0.125 to 0.25 mg twice daily every 3 days until panic disorder is controlled or until side effects make further increases undesired. Max adult dose: 4 mg/day PO. If discontinuation becomes necessary, gradually decrease by 0.125 mg twice daily every 3 days. The federal Omnibus Budget Reconciliation Act (OBRA) regulates the use of anxiolytics in long-term care facility (LTCF) residents. Max: 1.5 mg/day PO in residents meeting the criteria for treatment, except when documentation is provided showing that higher doses are necessary to maintain or improve the resident's functional status. In addition, the facility should attempt periodic tapering of the medication or provide documentation of medical necessity in accordance with OBRA guidelines.

    For the treatment of restless legs syndrome (RLS)†.
    Oral dosage
    Adults

    Dosage not established. Clonazepam use cannot be routinely recommended. Clonazepam appears to be effective for maintaining sleep, but efficacy in treating the primary symptoms of restless legs syndrome has not been established. Doses of 0.5 mg PO at bedtime up to 0.5 mg PO 3 times daily have not shown benefit in treating the primary symptoms of restless legs syndrome.

    For the treatment of insomnia†.
    Oral dosage
    Adults

    Doses of 0.25 to 0.5 mg PO at bedtime have been suggested.

    Geriatric Adults

    Doses of 0.25 to 0.5 mg PO at bedtime have been suggested for younger adults. Initiate treatment with half of the adult starting dose; the elderly are more sensitive to the effects of benzodiazepines. However, clonazepam should be avoided in the elderly if possible due to its long half-life and the availability of safer alternatives.

    For the treatment of central vestibular nystagmus† (e.g., downbeat nystagmus†) or acquired pendular nystagmus† or its variants (e.g., see-saw nystagmus†).
    Oral dosage
    Adults

    Optimal dosage not established; individualize based on clinical response and tolerance and use lowest effective dose. A single test dose helps determine response prior to maintenance treatment; the test dose will significantly reduce or alleviate symptoms in responders, such as oscillopsia. One uncontrolled case series (n = 5) of patients with idiopathic downbeat nystagmus used a 0.5 mg PO single test dose, followed by an electronystagmography (ENG) exam 1 hour later to assess response. Maintenance treatment with 1 mg PO twice daily was given to responders; clonazepam significantly reduced but did not permanently eliminate the nystagmus. Another case series (n = 10) suggests a 1 mg PO single test dose initially and ENG exam 1 hour later. Individualized maintenance doses (range: 0.25 mg to 2 mg per dose PO) were used, with administration times tailored to daily activity. Most received 0.25 mg to 1 mg PO twice daily. A review suggests the usual labeled doses for clonazepam (e.g., 0.5 mg PO 3 times daily initially, followed by dose titration by 0.5 to 1 mg PO every 3 days, not to exceed 20 mg/day PO).

    †Indicates off-label use

    MAXIMUM DOSAGE

    Adults

    20 mg/day PO.

    Geriatric

    20 mg/day PO.

    Adolescents

    > 30 kg: 20 mg/day PO for seizures; safety and efficacy have not been established for panic disorder.
    <= 30 kg: 0.1—0.2 mg/kg/day PO for seizures; safety and efficacy have not been established for panic disorder.

    Children

    0.1—0.2 mg/kg/day PO for seizures; safe and effective use not established for panic disorder.

    Infants

    0.1—0.2 mg/kg/day PO for seizures.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Dosage should be modified depending on clinical response and degree of hepatic impairment, but no quantitative recommendations are available. Clonazepam undergoes hepatic metabolism, and it is possible that liver disease will impair clonazepam elimination. The drug should not be used in patients with significant liver disease.

    Renal Impairment

    Dosage should be modified depending on clinical response and degree of renal impairment due to the fact that clonazepam metabolites are renally excreted, but no quantitative recommendations are available.

    ADMINISTRATION

     
    A MedGuide that discusses the risk of suicidal thoughts and behaviors associated with the use of anticonvulsant medications is available.

    Oral Administration

    Clonazepam may be administered orally without regard to meals.

    Oral Solid Formulations

    Conventional oral tablets: should be swallowed whole with a glass of water.
    Orally disintegrating tablets (wafer): Open the pouch by peeling back the foil on the blister pack. Do not push the tablet through the foil. Using dry hands, immediately remove the tablet and place in mouth. Tablet disintegration occurs rapidly and the dissolved tablet can be swallowed with or without water.

    STORAGE

    Ceberclon :
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Klonopin:
    - Store at controlled room temperature (between 68 and 77 degrees F)

    CONTRAINDICATIONS / PRECAUTIONS

    Benzodiazepine hypersensitivity

    Clonazepam is contraindicated in any patient with a known or suspected hypersensitivity to clonazepam, other benzodiazepine hypersensitivity, or with sensitivity to any component of the formulation.

    Depression, suicidal ideation

    In January 2008, the FDA alerted healthcare professionals of an increased risk of suicidal ideation and behavior in patients receiving anticonvulsants such as clonazepam to treat epilepsy, psychiatric disorders, or other conditions (e.g., migraine, neuropathic pain). This alert followed an initial request by the FDA in March 2005 for manufacturers of marketed anticonvulsants to provide data from existing controlled clinical trials for analysis. Prior to this request, preliminary evidence had suggested a possible link between anticonvulsant use and suicidality. The primary analysis consisted of 199 placebo-controlled clinical studies with a total of 27,863 patients in drug treatment groups and 16,029 patients in placebo groups (>= 5 years of age). There were 4 completed suicides among patients in drug treatment groups versus none in the placebo groups. Patients receiving anticonvulsants had approximately twice the risk of suicidal behavior or ideation (0.43%) as patients receiving placebo (0.24%), corresponding to an estimated 2.1 per 1000 (95% CI: 0.7—4.2) more patients in the drug treatment groups who experienced suicidal behavior or ideation. The relative risk for suicidality was higher in patients with epilepsy compared to those with other conditions; however, the absolute risk differences were similar in trials for epilepsy and psychiatric indications. Age was not a determining factor. The increased risk of suicidal ideation and behavior was observed between 1 and 24 weeks after therapy initiation. However, a longer duration of therapy should not preclude the possibility of an association to the drug since most studies included in the analysis did not continue beyond 24 weeks. Data were analyzed from drugs with adequately designed clinical trials including carbamazepine, felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, pregabalin, tiagabine, topiramate, valproate, and zonisamide. However, this is considered to be a class effect. All patients beginning treatment with anticonvulsants or currently receiving such treatment should be closely monitored for emerging or worsening depression or suicidal thoughts/behavior. Patients and caregivers should be informed of the increased risk of suicidal thoughts and behaviors and should be advised to immediately report the emergence or worsening of depression, the emergence of suicidal thoughts or behavior, thoughts of self-harm, or other unusual changes in mood or behavior. Anticonvulsants should be prescribed in the smallest quantity consistent with good patient management in order to reduce the risk of overdose.

    Bipolar disorder, mania

    Clonazepam should be used cautiously in patients with bipolar disorder because mania and hypomania have been reported in conjunction with the use of benzodiazepines in mood disorders.

    Asthma, bronchitis, chronic obstructive pulmonary disease (COPD), CNS depression, coadministration with other CNS depressants, coma, pulmonary disease, respiratory depression, shock, sleep apnea

    As with other benzodiazepines, clonazepam should be used with extreme caution in patients with pulmonary disease or conditions associated with compromised respiratory function such as sleep apnea, bronchitis, pneumonia, asthma, or chronic obstructive pulmonary disease (COPD). Additionally, avoid coadministration with other CNS depressants, especially opioids, unless no other alternatives are available as coadministration significantly increases the risk for respiratory depression, low blood pressure, and death. If coadministration is necessary, follow patients for signs and symptoms of respiratory depression and sedation. Clonazepam should not be used in patients with preexisting respiratory depression, cases of shock, or coma because the drug can worsen respiratory and CNS depression. In patients who snore regularly, partial airway obstruction may convert to obstructive sleep apnea with benzodiazepine administration. Clonazepam may produce hypersalivation and may aggravate conditions in which patients have difficulty handling secretions.

    Driving or operating machinery, ethanol ingestion, ethanol intoxication, psychosis

    Clonazepam, like other benzodiazepines, may cause CNS depression. Patients should be cautioned against driving or operating machinery until they know how clonazepam may affect them. Some patients may experience excessive sedation and impaired ability to perform tasks. Because clonazepam can cause drowsiness and a decreased level of consciousness, there is a higher risk of falls, particularly in the elderly, with the potential for subsequent severe injuries. The CNS depressant effects of benzodiazepines are additive to ethanol ingestion or other CNS depressants. Caution patients against use of alcohol during treatment with benzodiazepines. Use, particularly in the setting of ethanol intoxication, may cause marked CNS and respiratory depression and risk for death. Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Because of these risks, reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. In patients already receiving an opioid analgesic, prescribe a lower initial dose of the benzodiazepine and titrate based on clinical response. If an opioid is initiated in a patient already taking a benzodiazepine, prescribe a lower initial dose of the opioid and titrate based upon clinical response.

    Myasthenia gravis, neuromuscular disease, Parkinson's disease

    Clonazepam should be used with caution in patients with a neuromuscular disease, such as muscular dystrophy, myotonia, or myasthenia gravis as these conditions can be exacerbated. Patients with late stage Parkinson's disease may experience worsening of their psychosis or impaired cognition with administration of benzodiazepines. Benzodiazepines may also cause incoordination or paradoxical reactions that may worsen symptoms of Parkinson's disease. Clonazepam may infrequently increase the risk for hypersalivation and should be used cautiously in patients with Parkinson's disease.

    Seizure disorder, seizures

    When used in patients in whom several different types of seizure disorders coexist, clonazepam may increase the incidence or precipitate the onset of generalized tonic-clonic seizures. The addition of appropriate anticonvulsants or an increase in their dosages may be indicated. The concomitant use of valproic acid and clonazepam may produce absence status. Patients with a history of a seizure disorder should not be withdrawn abruptly from benzodiazepines due to the risk of precipitating a seizure. Flumazenil should not be used to reverse the actions of clonazepam in epileptic patients due to the risk of precipitating a seizure.

    Abrupt discontinuation, benzodiazepine dependence, status epilepticus, substance abuse

    Clonazepam can cause physical and psychological dependence, and should be used with extreme caution in patients with known, suspected, or history of substance abuse. Tolerance (or tachyphylaxis) may develop to the sedative effects of benzodiazepines. Loss of anticonvulsant activity has been reported in up to 30% of patients who initially respond to treatment, often within the first 3 months of administration. Dosage adjustment may reestablish efficacy, in some cases. Abrupt discontinuation of clonazepam after prolonged use should be avoided. Abrupt discontinuation of benzodiazepine therapy has been reported to cause withdrawal symptoms and status epilepticus, especially following high dose or prolonged therapy. However, benzodiazepine dependence can occur following administration of therapeutic doses for as few as 1 to 2 weeks, and withdrawal symptoms may be seen following the discontinuation of therapy. Patients with a seizure history or who are taking other drugs that lower the seizure threshold (i.e., TCAs, phenothiazines) should not be withdrawn abruptly from benzodiazepines due to the risk of precipitating a seizure. Clonazepam should be withdrawn slowly, using a gradual dosage-tapering schedule. During benzodiazepine withdrawal in general, the greatest risk of seizure appears to be during the first 24 to 72 hours. When clonazepam is being gradually withdrawn, the simultaneous substitution of another anticonvulsant may be indicated.

    Hepatic disease

    Clonazepam is contraindicated in patients with clinical or biochemical evidence of significant hepatic disease, as the drug undergoes hepatic metabolism.

    Renal failure, renal impairment

    Metabolites of clonazepam are excreted by the kidneys; to avoid their excess accumulation, caution should be exercised in the administration of the drug to patients with renal impairment or renal failure. In general, initial dose selection should be in the lower range and dosage titration should proceed cautiously. Assess renal function during prolonged therapy and adjust dosage as clinically indicated.

    Closed-angle glaucoma

    Clonazepam is contraindicated in patients with acute closed-angle glaucoma. Clonazepam may be used in patients with open angle glaucoma who are receiving appropriate therapy.

    Porphyria

    Clonazepam may have a porphyrogenic effect and should be used cautiously in patients with porphyria.

    Dementia, geriatric

    Clinical studies of clonazepam did not include sufficient numbers of geriatric patients to determine whether they respond differently from younger subjects. Reported clinical experience has not identified differences in responses between geriatric and younger adults. Sedatives may be associated with confusion and over-sedation in the older adult. Due to its long half-life and the availability of safer alternatives, clonazepam is not a preferred benzodiazepine for the treatment of insomnia in the elderly, and its use for this purpose should generally be avoided. Because clonazepam can cause drowsiness and a decreased level of consciousness, there is a higher risk of falls, particularly in the elderly, with the potential for subsequent severe injuries. If treatment with clonazepam is necessary in a geriatric patient, initiate treatment with a low dose followed by slow titration and close observation. Because geriatric patients are more likely to have decreased hepatic and/or renal function, care should be taken in clonazepam dose selection, and it may be useful to assess hepatic and/or renal function at the time of dose selection. According to the Beers Criteria, benzodiazepines are considered potentially inappropriate medications (PIMs) in geriatric patients and avoidance is generally recommended, although some agents may be appropriate for seizure disorders, rapid eye movement sleep disorders, benzodiazepine or ethanol withdrawal, severe generalized anxiety disorder, or peri-procedural anesthesia. Older adults have an increased sensitivity to benzodiazepines and slower metabolism of long-acting agents, which increases their risk of cognitive impairment, delirium, falls, fractures, and motor vehicle accidents. The Panel recommends avoiding benzodiazepines in geriatric patients with the following due to the potential for symptom exacerbation or adverse effects: delirium (new-onset or worsening delirium), dementia (adverse CNS effects), and history of falls/fractures (ataxia, impaired psychomotor function, syncope, and additional falls). If a benzodiazepine must be used in a patient with a history of falls or fractures, consider reducing use of other CNS-active medications that increase the risk of falls and fractures and implement other strategies to reduce fall risk. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities (LTCFs). Specific criteria for anxiolytics must be met, including 1) limiting use to indications specified in the OBRA guidelines (e.g., generalized anxiety disorder, panic disorder, significant anxiety to a situational trigger, alcohol withdrawal) which meet the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria for the indication, and 2) evidence exists that other possible reasons for the individual's distress have been considered, and 3) use results in maintenance or improvement in mental, physical, and psychosocial well-being as reflected on the Minimum Data Set (MDS) or other assessment tool. Anxiolytics should be used for delirium, dementia, or other cognitive disorders only when there are associated behaviors that are 1) quantitatively and objectively documented, and 2) are persistent, and 3) are not due to preventable or correctable reasons, and 4) constitute clinically significant distress or dysfunction to the LTCF resident or represent a danger to the resident or others. There are exceptions that may warrant the use of an anxiolytic such as a long-acting benzodiazepine for withdrawal from a short-acting benzodiazepine, use for neuromuscular syndromes (e.g., tardive dyskinesia, restless legs syndrome, seizure disorder, cerebral palsy), or palliative care. The need for indefinite continuation of clonazepam (e.g., seizure disorder) should be based on confirmation of the condition being treated and its potential cause(s). Benzodiazepines may increase the risk of confusion, sedation, and falls. OBRA provides dosing guidance for clonazepam as an anxiolytic. When a medication is used to manage behavior, stabilize mood, or treat a psychiatric disorder, the facility should attempt periodic tapering of the medication or provide documentation of medical necessity in accordance with OBRA guidelines.

    Labor, neonates, obstetric delivery, pregnancy

    There are no adequate and well-controlled studies of clonazepam in pregnant women. Available human data on the risk of teratogenicity are inconclusive. There is insufficient evidence in humans to assess the effect of benzodiazepine exposure during pregnancy on neurodevelopment. Perinatal complications have been reported in neonates born to mothers who have been receiving benzodiazepines late in pregnancy, including findings suggestive of either excess benzodiazepine exposure or of withdrawal phenomena. Symptoms of perinatal problems in the exposed neonate may include hypothermia, hypotonia, respiratory depression, and difficulty feeding. Animal data indicate teratogenic effects of clonazepam. Pregnant rabbits were given clonazepam doses lower or similar to maximum human doses during the period of organogenesis. Cleft palate, open eyelid, fused sternebrae, and limb defects were observed in a low, non-dose related incidence in exposed litters from all dosage groups. No maternal or embryo-fetal anomalies were noted in mice and rats receiving 4 and 20 times the maximum recommended human dose. Clonazepam has not been studied for use during labor or obstetric delivery. Physicians are advised to recommend that pregnant patients receiving clonazepam enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry to provide information about the effects of in utero exposure to the drug. This can be done by calling the registry at 1-888-233-2334, and must be done by patients themselves. Information on this registry can also be found at the website www.aedpregnancyregistry.org.

    Breast-feeding

    Avoid prolonged use of clonazepam during breast-feeding, and consider alternative shorter-acting drugs, such as lorazepam. Clonazepam is excreted in breast milk in low concentrations with a milk to plasma ratio of approximately 0.3. However, drug accumulation may occur in the infant due to a long half-life. Sedative effects in the infant, with resultant poor feeding, have been occasionally reported with maternal use of clonazepam. Observational studies suggest that benzodiazepine use, including the use of clonazepam, does not prohibit the initiation of breast-feeding, and that continued maternal use may ensue with close monitoring of the breast-fed infant for sedation, poor feeding, problems with weight gain, and apnea; however, more study is needed. Previous American Academy of Pediatrics (AAP) recommendations considered benzodiazepines to be drugs whose effect on the nursing infant is not known but may be of concern, particularly with prolonged exposure. Consider the developmental and health benefits of breast-feeding along with the mother's clinical need for clonazepam and any potential adverse effects on the breast-fed infant from clonazepam or the underlying maternal condition.

    Children, infants

    Long-term administration of clonazepam to adolescents, children, and infants with seizure activity should be carefully considered via a benefit-risk evaluation, given the possibility that adverse effects on physical or mental development could become apparent only after many years. Safety and effectiveness of clonazepam have not been established for treating panic disorder in patients pediatric patients under the age of 18 years.

    ADVERSE REACTIONS

    Severe

    suicidal ideation / Delayed / 0.4-0.4
    coma / Early / Incidence not known
    teratogenesis / Delayed / Incidence not known
    visual impairment / Early / Incidence not known

    Moderate

    ataxia / Delayed / 1.0-30.0
    depression / Delayed / 6.0-8.0
    memory impairment / Delayed / 2.0-5.0
    constipation / Delayed / 0-5.0
    dysarthria / Delayed / 3.0-4.0
    vaginitis / Delayed / 0-4.0
    impotence (erectile dysfunction) / Delayed / 0-3.0
    blurred vision / Early / 0-3.0
    confusion / Early / 1.0-2.0
    paresis / Delayed / 0.1-1.0
    migraine / Early / 0.1-1.0
    excitability / Early / 0.1-1.0
    hemorrhoids / Delayed / 0.1-1.0
    candidiasis / Delayed / 0.1-1.0
    dyspnea / Early / 0.1-1.0
    cystitis / Delayed / 0.1-1.0
    bleeding / Early / 0.1-1.0
    dysuria / Early / 0.1-1.0
    urinary retention / Early / 0.1-1.0
    urinary incontinence / Early / 0.1-1.0
    hypertonia / Delayed / 0.1-1.0
    contact dermatitis / Delayed / 0.1-1.0
    orthostatic hypotension / Delayed / 0.1-1.0
    edema / Delayed / 0.1-1.0
    chest pain (unspecified) / Early / 0.1-1.0
    palpitations / Early / 0.1-1.0
    gout / Delayed / 0.1-1.0
    tolerance / Delayed / Incidence not known
    physiological dependence / Delayed / Incidence not known
    psychological dependence / Delayed / Incidence not known
    amnesia / Delayed / Incidence not known
    hostility / Early / Incidence not known
    psychosis / Early / Incidence not known
    hallucinations / Early / Incidence not known
    fecal incontinence / Early / Incidence not known
    gastritis / Delayed / Incidence not known
    withdrawal / Early / Incidence not known
    respiratory depression / Rapid / Incidence not known
    lymphadenopathy / Delayed / Incidence not known
    hypotonia / Delayed / Incidence not known
    nystagmus / Delayed / Incidence not known
    thrombocytopenia / Delayed / Incidence not known
    anemia / Delayed / Incidence not known
    eosinophilia / Delayed / Incidence not known
    elevated hepatic enzymes / Delayed / Incidence not known
    leukopenia / Delayed / Incidence not known
    hepatomegaly / Delayed / Incidence not known
    dehydration / Delayed / Incidence not known

    Mild

    drowsiness / Early / 26.0-50.0
    dizziness / Early / 5.0-12.0
    infection / Delayed / 0-10.0
    fatigue / Early / 6.0-9.0
    sinusitis / Delayed / 2.0-8.0
    dysmenorrhea / Delayed / 0-6.0
    influenza / Delayed / 2.0-5.0
    rhinitis / Early / 2.0-4.0
    cough / Delayed / 0-4.0
    myalgia / Early / 0-4.0
    anorexia / Delayed / 0-3.0
    pharyngitis / Delayed / 1.0-3.0
    libido decrease / Delayed / 0-3.0
    emotional lability / Early / 0-2.0
    abdominal pain / Early / 0-2.0
    increased urinary frequency / Early / 1.0-2.0
    paresthesias / Delayed / 0.1-1.0
    tremor / Early / 0.1-1.0
    shivering / Rapid / 0.1-1.0
    hypoesthesia / Delayed / 0.1-1.0
    vertigo / Early / 0.1-1.0
    yawning / Early / 0.1-1.0
    nightmares / Early / 0.1-1.0
    anxiety / Delayed / 0.1-1.0
    insomnia / Early / 0.1-1.0
    dyspepsia / Early / 0.1-1.0
    weight gain / Delayed / 0.1-1.0
    flatulence / Early / 0.1-1.0
    dysgeusia / Early / 0.1-1.0
    weight loss / Delayed / 0.1-1.0
    pyrosis (heartburn) / Early / 0.1-1.0
    appetite stimulation / Delayed / 0.1-1.0
    hypersalivation / Early / 0.1-1.0
    fever / Early / 0.1-1.0
    epistaxis / Delayed / 0.1-1.0
    hoarseness / Early / 0.1-1.0
    sneezing / Early / 0.1-1.0
    urine discoloration / Early / 0.1-1.0
    libido increase / Delayed / 0.1-1.0
    menstrual irregularity / Delayed / 0.1-1.0
    polyuria / Early / 0.1-1.0
    back pain / Delayed / 0.1-1.0
    musculoskeletal pain / Early / 0.1-1.0
    muscle cramps / Delayed / 0.1-1.0
    arthralgia / Delayed / 0.1-1.0
    diplopia / Early / 0.1-1.0
    xerophthalmia / Early / 0.1-1.0
    alopecia / Delayed / 0.1-1.0
    flushing / Rapid / 0.1-1.0
    pruritus / Rapid / 0.1-1.0
    acne vulgaris / Delayed / 0.1-1.0
    headache / Early / Incidence not known
    irritability / Delayed / Incidence not known
    agitation / Early / Incidence not known
    nausea / Early / Incidence not known
    diarrhea / Early / Incidence not known
    rhinorrhea / Early / Incidence not known
    nocturia / Early / Incidence not known
    weakness / Early / Incidence not known
    rash / Early / Incidence not known
    hirsutism / Delayed / Incidence not known

    DRUG INTERACTIONS

    Acetaminophen; Aspirin, ASA; Caffeine: (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Acetaminophen; Butalbital: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Acetaminophen; Butalbital; Caffeine: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur. (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Acetaminophen; Butalbital; Caffeine; Codeine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines. (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur. (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Acetaminophen; Caffeine: (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Acetaminophen; Caffeine; Dihydrocodeine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines. (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Acetaminophen; Caffeine; Magnesium Salicylate; Phenyltoloxamine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Acetaminophen; Caffeine; Phenyltoloxamine; Salicylamide: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Acetaminophen; Chlorpheniramine; Phenylephrine; Phenyltoloxamine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Acetaminophen; Codeine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
    Acetaminophen; Dextromethorphan; Doxylamine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Acetaminophen; Dichloralphenazone; Isometheptene: (Moderate) The CNS depressant effects of dichloralphenazone can be potentiated by benzodiazepines.
    Acetaminophen; Diphenhydramine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Acetaminophen; Guaifenesin; Phenylephrine: (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Acetaminophen; Hydrocodone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines.
    Acetaminophen; Oxycodone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If oxycodone is initiated in a patient taking a benzodiazepine, reduce dosages and titrate to clinical response. For acetaminophen; oxycodone extended-release tablets, start with 1 tablet PO every 12 hours, and for other oxycodone products, use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Acetaminophen; Pentazocine: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Acetaminophen; Propoxyphene: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. The dose of any opiate agonist administered with parenteral diazepam should be reduced by at least one-third.
    Acetaminophen; Tramadol: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Acrivastine; Pseudoephedrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Aldesleukin, IL-2: (Moderate) Aldesleukin, IL-2 may affect CNS function significantly. Therefore, psychotropic pharmacodynamic interactions could occur following concomitant administration of drugs with significant CNS activity. Use with caution.
    Alfentanil: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Alprazolam: (Moderate) Concomitant administration of alprazolam with CNS-depressant drugs can potentiate the CNS effects of either agent.
    Amiodarone: (Moderate) Amiodarone is a CYP3A4 inhibitor and may reduce the metabolism of clonazepam and increase the potential for benzodiazepine toxicity.
    Amobarbital: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Amoxapine: (Moderate) Amoxapine may enhance the response to the effects of benzodiazepines and other CNS depressants. Patients should be warned of the possibility of drowsiness that may impair performance of potentially hazardous tasks such as driving an automobile or operating machinery.
    Amoxicillin; Clarithromycin; Lansoprazole: (Moderate) Use clarithromycin cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Clarithromycin is a CYP3A4 inhibitor.
    Amoxicillin; Clarithromycin; Omeprazole: (Moderate) Omeprazole inhibits CYP2C19. There have been some case reports describing an interaction between omeprazole and benzodiazepines metabolized via the cytochrome P450 system, such as clonazepam. Patients should be monitored to determine if it is necessary to adjust the dosage of the benzodiazepine when taken concomitantly with omeprazole. (Moderate) Use clarithromycin cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Clarithromycin is a CYP3A4 inhibitor.
    Amphetamine; Dextroamphetamine Salts: (Major) Patients who are taking anticonvulsants for epilepsy/seizure control should use amphetamine; dextroamphetamine with caution. Amphetamines may decrease the seizure threshold and may increase the risk of seizures.
    Amprenavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Apalutamide: (Moderate) Monitor patients for decreased efficacy and a change in clonazepam dosage requirements when giving concurrently with apalutamide. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate and apalutamide is a strong CYP3A4 inducer.
    Apomorphine: (Moderate) Apomorphine causes significant somnolence. Concomitant administration of apomorphine and CNS depressants could result in additive depressant effects.
    Apraclonidine: (Minor) No specific drug interactions were identified with systemic agents and apraclonidine during clinical trials. Theoretically, apraclonidine might potentiate the effects of CNS depressant drugs such as the anxiolytics, sedatives, and hypnotics, including barbiturates or benzodiazepines.
    Aprepitant, Fosaprepitant: (Major) Use caution if clonazepam and aprepitant, fosaprepitant are used concurrently and monitor for an increase in clonazepam-related adverse effects for several days after administration of a multi-day aprepitant regimen. If a benzodiazepine is necessary, a dosage adjustment of the multi-day regimen may be necessary depending on the clinical situation (e.g., elderly patients) and degree of monitoring available; no dosage adjustment is needed for a single 40-mg dose of aprepitant or 150-mg dose of fosaprepitant. Consider selection of an agent that is not metabolized via CYP3A4 isoenzymes (e.g., lorazepam, oxazepam, temazepam). Clonazepam is a CYP3A4 substrate. Aprepitant, when administered as a 3-day oral regimen (125 mg/80 mg/80 mg), is a moderate CYP3A4 inhibitor and inducer and may increase plasma concentrations of clonazepam. For example, a 5-day oral aprepitant regimen increased the AUC of another CYP3A4 substrate, midazolam (single dose), by 2.3-fold on day 1 and by 3.3-fold on day 5. After a 3-day oral aprepitant regimen, the AUC of midazolam (given on days 1, 4, 8, and 15) increased by 25% on day 4, and then decreased by 19% and 4% on days 8 and 15, respectively. As a single 125 mg or 40 mg oral dose, the inhibitory effect of aprepitant on CYP3A4 is weak, with the AUC of midazolam increased by 1.5-fold and 1.2-fold, respectively. After administration, fosaprepitant is rapidly converted to aprepitant and shares many of the same drug interactions. However, as a single 150 mg intravenous dose, fosaprepitant only weakly inhibits CYP3A4 for a duration of 2 days; there is no evidence of CYP3A4 induction. Fosaprepitant 150 mg IV as a single dose increased the AUC of midazolam (given on days 1 and 4) by approximately 1.8-fold on day 1; there was no effect on day 4. Less than a 2-fold increase in the midazolam AUC is not considered clinically important.
    Aripiprazole: (Moderate) Due to the primary CNS effects of aripiprazole, caution should be used when aripiprazole is given in combination with other centrally-acting medications including benzodiazepines and other anxiolytics, sedatives, and hypnotics. The intensity of sedation and orthostatic hypotension is greater during concurrent use of lorazepam and oral aripiprazole and during use of a parenteral benzodiazepine and intramuscular (IM) aripiprazole compared to aripiprazole alone; therefore, patients receiving a benzodiazepine with oral or parenteral aripiprazole should be monitored for sedation and blood pressure and the dose should be adjusted accordingly. Data from the manufacturer indicate there are no clinically significant pharmacokinetic changes when aripiprazole is given with lorazepam.
    Asenapine: (Moderate) Drugs that can cause CNS depression, if used concomitantly with asenapine, may increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, and dizziness. Caution should be used when asenapine is given in combination with other centrally-acting medications including anxiolytics, sedatives, and hypnotics (including barbiturates), buprenorphine, buprenorphine; naloxone, butorphanol, dronabinol, THC, nabilone, nalbuphine, opiate agonists, pentazocine, acetaminophen; pentazocine, aspirin, ASA; pentazocine, and pentazocine; naloxone.
    Aspirin, ASA; Butalbital; Caffeine: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur. (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Aspirin, ASA; Butalbital; Caffeine; Codeine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines. (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur. (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Aspirin, ASA; Caffeine; Dihydrocodeine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines. (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Aspirin, ASA; Caffeine; Orphenadrine: (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Aspirin, ASA; Carisoprodol; Codeine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
    Aspirin, ASA; Omeprazole: (Moderate) Omeprazole inhibits CYP2C19. There have been some case reports describing an interaction between omeprazole and benzodiazepines metabolized via the cytochrome P450 system, such as clonazepam. Patients should be monitored to determine if it is necessary to adjust the dosage of the benzodiazepine when taken concomitantly with omeprazole.
    Aspirin, ASA; Oxycodone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If oxycodone is initiated in a patient taking a benzodiazepine, reduce dosages and titrate to clinical response. For acetaminophen; oxycodone extended-release tablets, start with 1 tablet PO every 12 hours, and for other oxycodone products, use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Atazanavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Atazanavir; Cobicistat: (Moderate) Monitor for increased sedation and respiratory depression if clonazepam is coadministered with cobicistat; adjust the dose of clonazepam if necessary. The systemic exposure of clonazepam may be increased resulting in increase in treatment-related adverse reactions. Cobicistat is a strong CYP3A4 inhibitor and clonazepam is a CYP3A4 substrate. (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Atracurium: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Atropine; Difenoxin: (Moderate) Concomitant administration of benzodiazepines with CNS-depressant drugs, such as diphenoxylate/difenoxin, can potentiate the CNS effects of either agent.
    Atropine; Diphenoxylate: (Moderate) Concomitant administration of benzodiazepines with CNS-depressant drugs, such as diphenoxylate/difenoxin, can potentiate the CNS effects of either agent.
    Atropine; Hyoscyamine; Phenobarbital; Scopolamine: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur. (Moderate) Scopolamine may cause dizziness and drowsiness. Concurrent use of scopolamine and CNS depressants can adversely increase the risk of CNS depression.
    Azelastine: (Moderate) An enhanced CNS depressant effect may occur when azelastine is combined with CNS depressants including benzodiazepines.
    Azelastine; Fluticasone: (Moderate) An enhanced CNS depressant effect may occur when azelastine is combined with CNS depressants including benzodiazepines.
    Barbiturates: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Belladonna Alkaloids; Ergotamine; Phenobarbital: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Belladonna; Opium: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Benzhydrocodone; Acetaminophen: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If benzhydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Benztropine: (Moderate) CNS depressants, such as anxiolytics, sedatives, and hypnotics, can increase the sedative effects of benztropine.
    Boceprevir: (Moderate) Close clinical monitoring is advised when administering clonazepam with boceprevir due to an increased potential for clonazepam-related adverse events. If clonazepam dose adjustments are made, re-adjust the dose upon completion of boceprevir treatment. Although this interaction has not been studied, predictions about the interaction can be made based on the metabolic pathway of clonazepam. Clonazepam is metabolized by the hepatic isoenzyme CYP3A4; boceprevir inhibits this isoenzyme. Coadministration may result in elevated clonazepam plasma concentrations.
    Bosentan: (Moderate) Bosentan is a hepatic inducer and can theoretically increase the clearance of benzodiazepines metabolized by oxidative metabolism leading to lower benzodiazepine concentrations.
    Brimonidine: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of the anxiolytics, sedatives, and hypnotics including benzodiazepines.
    Brimonidine; Brinzolamide: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of the anxiolytics, sedatives, and hypnotics including benzodiazepines.
    Brimonidine; Timolol: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of the anxiolytics, sedatives, and hypnotics including benzodiazepines.
    Brompheniramine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Brompheniramine; Carbetapentane; Phenylephrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including benzodiazepines. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Brompheniramine; Dextromethorphan; Guaifenesin: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Brompheniramine; Guaifenesin; Hydrocodone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Brompheniramine; Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Brompheniramine; Pseudoephedrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Buprenorphine: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated for pain in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. Reduce injectable buprenorphine dose by 1/2, and for the buprenorphine transdermal patch, start therapy with the 5 mcg/hour patch. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. In patients treated with buprenorphine for opioid use disorder, cessation of benzodiazepines or other CNS depressants is preferred in most cases. Consider alternatives to benzodiazepines for conditions such as anxiety or insomnia in patients receiving buprenorphine maintenance treatment. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Buprenorphine; Naloxone: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated for pain in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. Reduce injectable buprenorphine dose by 1/2, and for the buprenorphine transdermal patch, start therapy with the 5 mcg/hour patch. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. In patients treated with buprenorphine for opioid use disorder, cessation of benzodiazepines or other CNS depressants is preferred in most cases. Consider alternatives to benzodiazepines for conditions such as anxiety or insomnia in patients receiving buprenorphine maintenance treatment. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Buspirone: (Moderate) It is common for patients to overlap anxiety treatment when switching from benzodiazepines to buspirone. Buspirone has a slow onset of action and the drug will not block the withdrawal syndrome often seen with cessation of benzodiazepine therapy in those with benzodiazepine dependence. Therefore, before starting therapy with buspirone, withdraw patients gradually from the benzodiazepine. Alternatively, conversion to buspirone therapy may require treatment overlap to allow for the downward titration of the benzodiazepine while buspirone takes effect. It should be noted that the combination of buspirone and benzodiazepines can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent.
    Butabarbital: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Butorphanol: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Caffeine: (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Caffeine; Ergotamine: (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Cannabidiol: (Moderate) Monitor for excessive sedation and somnolence during coadministration of cannabidiol and clonazepam. CNS depressants can potentiate the effects of cannabidiol.
    Carbamazepine: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with carbamazepine due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Carbamazepine is a strong CYP3A4 inducer. Additive CNS depression may also occur.
    Carbetapentane; Chlorpheniramine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including benzodiazepines.
    Carbetapentane; Chlorpheniramine; Phenylephrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including benzodiazepines. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Carbetapentane; Diphenhydramine; Phenylephrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including benzodiazepines. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Carbetapentane; Guaifenesin: (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including benzodiazepines.
    Carbetapentane; Guaifenesin; Phenylephrine: (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including benzodiazepines. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Carbetapentane; Phenylephrine: (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including benzodiazepines. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Carbetapentane; Phenylephrine; Pyrilamine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including benzodiazepines. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Carbetapentane; Pseudoephedrine: (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including benzodiazepines.
    Carbetapentane; Pyrilamine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including benzodiazepines.
    Carbinoxamine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Carbinoxamine; Dextromethorphan; Pseudoephedrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Carbinoxamine; Hydrocodone; Phenylephrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Carbinoxamine; Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Carbinoxamine; Phenylephrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Carbinoxamine; Pseudoephedrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Cariprazine: (Moderate) Due to the CNS effects of cariprazine, caution should be used when cariprazine is given in combination with other centrally-acting medications including benzodiazepines and other anxiolytics, sedatives, and hypnotics.
    Ceritinib: (Moderate) Monitor for increased sedation and respiratory depression if clonazepam is coadministered with ceritinib; adjust the dose of clonazepam if necessary. The systemic exposure of clonazepam may be increased resulting in increase in treatment-related adverse reactions. Ceritinib is a strong CYP3A4 inhibitor and clonazepam is a CYP3A4 substrate.
    Cetirizine: (Moderate) Concurrent use of cetirizine/levocetirizine with benzodiazepines should generally be avoided. Coadministration may increase the risk of CNS depressant-related side effects. If concurrent use is necessary, monitor for excessive sedation and somnolence.
    Cetirizine; Pseudoephedrine: (Moderate) Concurrent use of cetirizine/levocetirizine with benzodiazepines should generally be avoided. Coadministration may increase the risk of CNS depressant-related side effects. If concurrent use is necessary, monitor for excessive sedation and somnolence.
    Chlophedianol; Dexbrompheniramine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlophedianol; Guaifenesin; Phenylephrine: (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Chlorcyclizine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlorpheniramine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlorpheniramine; Codeine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlorpheniramine; Dextromethorphan: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Chlorpheniramine; Dihydrocodeine; Pseudoephedrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlorpheniramine; Guaifenesin; Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlorpheniramine; Hydrocodone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlorpheniramine; Hydrocodone; Phenylephrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Chlorpheniramine; Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlorpheniramine; Phenylephrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Chlorpheniramine; Pseudoephedrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Chlorthalidone; Clonidine: (Moderate) Clonidine has CNS depressive effects and can potentiate the actions of other CNS depressants including benzodiazepines.
    Cimetidine: (Moderate) Cimetidine can decrease the hepatic oxidative metabolism of clonazepam if administered concomitantly.
    Ciprofloxacin: (Moderate) Ciprofloxacin is a CYP3A4 inhibitor and may reduce the metabolism of clonazepam and increase the potential for benzodiazepine toxicity.
    Cisapride: (Moderate) Cisapride may enhance the sedative effects of benzodiazepines. Patients should not drive or operate heavy machinery until they know how the combination affects them. Patient counseling is important, as cisapride alone does not cause drowsiness or affect psychomotor function.
    Cisatracurium: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Clarithromycin: (Moderate) Use clarithromycin cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Clarithromycin is a CYP3A4 inhibitor.
    Clemastine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Clobazam: (Moderate) Use clobazam with other benzodiazepines with caution due to the potential for increased risk of drowsiness and sedation.
    Clonidine: (Moderate) Clonidine has CNS depressive effects and can potentiate the actions of other CNS depressants including benzodiazepines.
    Clozapine: (Moderate) If concurrent therapy with clozapine and a benzodiazepine is necessary, it is advisable to begin with the lowest possible benzodiazepine dose and closely monitor the patient, particularly at initiation of treatment and following dose increases. Although the combination has been used safely, adverse reactions such as confusion, ataxia, somnolence, delirium, collapse, cardiac arrest, respiratory arrest, and death have occurred rarely in patients receiving clozapine concurrently or following benzodiazepine therapy. Several benzodiazepines, including clonazepam, oxazepam, flurazepam, diazepam, clobazam, flunitrazepam, and lorazepam have been implicated in these reactions. At least one case of sudden death was reported following intravenous administration of lorazepam to a patient receiving clozapine.
    Cobicistat: (Moderate) Monitor for increased sedation and respiratory depression if clonazepam is coadministered with cobicistat; adjust the dose of clonazepam if necessary. The systemic exposure of clonazepam may be increased resulting in increase in treatment-related adverse reactions. Cobicistat is a strong CYP3A4 inhibitor and clonazepam is a CYP3A4 substrate.
    Codeine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
    Codeine; Guaifenesin: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
    Codeine; Phenylephrine; Promethazine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Codeine; Promethazine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
    Colchicine; Probenecid: (Moderate) Probenecid may inhibit the metabolism of the benzodiazepines, including those which are metabolized by conjugation (e.g., lorazepam) or oxidation (e.g., midazolam). Probenecid has been shown to decrease lorazepam clearance by about 50% and increase its elimination half-life. In addition, pretreatment with probenecid shortened the induction time (85 vs. 109 seconds) of midazolam in presurgical patients. Patients receiving alprazolam therapy should be monitored for signs of altered benzodiazepine response when probenecid is initiated or discontinued.
    Colesevelam: (Moderate) The manufacturer for colesevelam suggests monitoring serum drug concentrations and/or clinical effects for those drugs for which alterations in serum blood concentrations have a clinically significant effect on safety or efficacy. To minimize potential for interactions, consider administering oral anticonvulsants such as clonazepam at least 4 hours before colesevelam.
    COMT inhibitors: (Moderate) Concomitant administration of benzodiazepines with CNS-depressant drugs, including COMT inhibitors, can potentiate the CNS effects of either agent.
    Conivaptan: (Major) Concomitant use of conivaptan and clonazepam, a CYP3A4 substrate, should be avoided. Conivaptan is a potent inhibitor of CYP3A4 and may increase plasma concentrations of drugs that are primarily metabolized by CYP3A4. Intravenous conivaptan 40 mg/day increases the mean midazolam AUC values by approximately 2-fold and 3-fold when coadministered with 1 mg IV and 2 mg PO, respectively, of midazolam, another CYP3A4 substrate. Theoretically, similar pharmacokinetic effects could be seen with clonazepam. Subsequent treatment with CYP3A substrates, such as clonazepam, may be initiated no sooner than 1 week after completion of conivaptan therapy.
    Crizotinib: (Moderate) Monitor for an increase in clonazepam-related adverse reactions including sedation and respiratory depression if coadministration with crizotinib is necessary; adjust the dose of clonazepam if necessary. Crizotinib is a moderate CYP3A inhibitor and clonazepam is a CYP3A substrate. Although clinical studies have not been performed, based on the involvement of CYP3A in clonazepam metabolism, inhibitors of this enzyme system may increase clonazepam exposure and should be used cautiously.
    Cyclizine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Cyproheptadine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Danazol: (Moderate) Danazol is a CYP3A4 inhibitor and can decrease the hepatic metabolism of clonazepam, a CYP3A4 substrate.
    Darunavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Darunavir; Cobicistat: (Moderate) Monitor for increased sedation and respiratory depression if clonazepam is coadministered with cobicistat; adjust the dose of clonazepam if necessary. The systemic exposure of clonazepam may be increased resulting in increase in treatment-related adverse reactions. Cobicistat is a strong CYP3A4 inhibitor and clonazepam is a CYP3A4 substrate. (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Moderate) Monitor for increased sedation and respiratory depression if clonazepam is coadministered with cobicistat; adjust the dose of clonazepam if necessary. The systemic exposure of clonazepam may be increased resulting in increase in treatment-related adverse reactions. Cobicistat is a strong CYP3A4 inhibitor and clonazepam is a CYP3A4 substrate. (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Delavirdine: (Moderate) Use delavirdine cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Delavirdine is a CYP3A4 inhibitor.
    Desflurane: (Moderate) Concurrent use with benzodiazepines can decrease the minimum alveolar concentration (MAC) of desflurane needed to produce anesthesia.
    Deutetrabenazine: (Moderate) Advise patients that concurrent use of deutetrabenazine and drugs that can cause CNS depression, such as clonazepam, may have additive effects and worsen drowsiness or sedation.
    Dexchlorpheniramine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Dexmedetomidine: (Moderate) Co-administration of dexmedetomidine with benzodiazepines is likely to lead to an enhancement of CNS depression.
    Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Dicyclomine: (Moderate) Dicyclomine can cause drowsiness, so it should be used cautiously in patients receiving CNS depressants like benzodiazepines.
    Dihydrocodeine; Guaifenesin; Pseudoephedrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
    Diltiazem: (Moderate) CYP3A4 inhibitors, such as diltiazem, may reduce the metabolism of clonazepam and increase the potential for benzodiazepine toxicity.
    Dimenhydrinate: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Diphenhydramine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Diphenhydramine; Hydrocodone; Phenylephrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines. (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Diphenhydramine; Ibuprofen: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Diphenhydramine; Naproxen: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Diphenhydramine; Phenylephrine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Disulfiram: (Moderate) Disulfiram can decrease the hepatic oxidative metabolism of clonazepam if administered concomitantly. Patients receiving clonazepam should be monitored for signs of an exaggerated response if disulfiram is used concomitantly.
    Doxacurium: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Doxylamine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Doxylamine; Pyridoxine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Dronabinol: (Moderate) Use caution if the use of benzodiazepines are necessary with dronabinol, and monitor for additive dizziness, confusion, somnolence, and other CNS effects.
    Dronedarone: (Moderate) Dronedarone is metabolized by and is an inhibitor of CYP3A. Clonazepam is a substrate for CYP3A4. The concomitant administration of dronedarone and CYP3A substrates may result in increased exposure of the substrate and should, therefore, be undertaken with caution.
    Droperidol: (Major) Droperidol administration is associated with an established risk for QT prolongation and torsades de pointes. In December 2001, the FDA issued a black box warning regarding the use of droperidol and its association with QT prolongation and potential for cardiac arrhythmias based on post-marketing surveillance data. Risk factors for the development of prolonged QT syndrome may include the use of benzodiazepines. Also, droperidol and benzodiazepines can both cause CNS depression. If used with a benzodiazepine, droperidol should be initiated at a low dose and adjusted upward, with caution, as needed to achieve the desired effect.
    Drospirenone; Ethinyl Estradiol: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Drospirenone; Ethinyl Estradiol; Levomefolate: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Efavirenz: (Moderate) In vivo, efavirenz has been shown to induce hepatic enzymes CYP3A4 and CYP2B6. Patients receiving benzodiazepines that are metabolized by these isoenzymes may experience decreased benzodiazepine serum concentrations, if administered concurrently with efavirenz. Efavirenz should be used with caution with oxidized benzodiazepines including (e.g., clonazepam). Monitor patients closely for excessive side effects.
    Efavirenz; Emtricitabine; Tenofovir: (Moderate) In vivo, efavirenz has been shown to induce hepatic enzymes CYP3A4 and CYP2B6. Patients receiving benzodiazepines that are metabolized by these isoenzymes may experience decreased benzodiazepine serum concentrations, if administered concurrently with efavirenz. Efavirenz should be used with caution with oxidized benzodiazepines including (e.g., clonazepam). Monitor patients closely for excessive side effects.
    Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Moderate) In vivo, efavirenz has been shown to induce hepatic enzymes CYP3A4 and CYP2B6. Patients receiving benzodiazepines that are metabolized by these isoenzymes may experience decreased benzodiazepine serum concentrations, if administered concurrently with efavirenz. Efavirenz should be used with caution with oxidized benzodiazepines including (e.g., clonazepam). Monitor patients closely for excessive side effects.
    Elbasvir; Grazoprevir: (Moderate) Administering clonazepam with elbasvir; grazoprevir may result in elevated clonazepam plasma concentrations. Clonazepam 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: (Moderate) Monitor for increased sedation and respiratory depression if clonazepam is coadministered with cobicistat; adjust the dose of clonazepam if necessary. The systemic exposure of clonazepam may be increased resulting in increase in treatment-related adverse reactions. Cobicistat is a strong CYP3A4 inhibitor and clonazepam is a CYP3A4 substrate.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Moderate) Monitor for increased sedation and respiratory depression if clonazepam is coadministered with cobicistat; adjust the dose of clonazepam if necessary. The systemic exposure of clonazepam may be increased resulting in increase in treatment-related adverse reactions. Cobicistat is a strong CYP3A4 inhibitor and clonazepam is a CYP3A4 substrate.
    Enflurane: (Moderate) Concomitant administration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent.
    Enzalutamide: (Moderate) Monitor patients for decreased efficacy and a change in clonazepam dosage requirements when giving concurrently with enzalutamide. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate and enzalutamide is a strong CYP3A4 inducer.
    Erythromycin: (Moderate) Erythromycin may inhibit the CYP3A4-mediated metabolism of oxidized benzodiazepines, such as clonazepam. Monitor patient clinically for enhanced clonazepam response.
    Erythromycin; Sulfisoxazole: (Moderate) Erythromycin may inhibit the CYP3A4-mediated metabolism of oxidized benzodiazepines, such as clonazepam. Monitor patient clinically for enhanced clonazepam response.
    Esketamine: (Major) Closely monitor patients receiving esketamine and benzodiazepines for sedation and other CNS depressant effects. Instruct patients who receive a dose of esketamine not to drive or engage in other activities requiring alertness until the next day after a restful sleep.
    Eszopiclone: (Moderate) Concomitant administration of benzodiazepines with eszopiclone can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. The concurrent use of eszopiclone with other anxiolytics, sedatives, and hypnotics at bedtime or in the middle of the night is not recommended. In addition, the risk of next-day psychomotor impairment is increased during co-administration of eszopiclone and other CNS depressants, which may decrease the ability to perform tasks requiring full mental alertness such as driving. If used together, a reduction in the dose of one or both drugs may be needed.
    Ethanol: (Major) Alcohol is associated with CNS depression. The combined use of alcohol and CNS depressants can lead to additive CNS depression, which could be dangerous in tasks requiring mental alertness and fatal in overdose. Alcohol taken with other CNS depressants can lead to additive respiratory depression, hypotension, profound sedation, or coma. Consider the patient's use of alcohol or illicit drugs when prescribing CNS depressant medications. In many cases, the patient should receive a lower dose of the CNS depressant initially if the patient is not likely to be compliant with avoiding alcohol.
    Ethinyl Estradiol: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Desogestrel: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Ethynodiol Diacetate: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Etonogestrel: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Levonorgestrel: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Levonorgestrel; Ferrous bisglycinate: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Levonorgestrel; Folic Acid; Levomefolate: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Norelgestromin: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Norethindrone Acetate: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Norethindrone Acetate; Ferrous fumarate: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Norethindrone: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Norethindrone; Ferrous fumarate: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Norgestimate: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethinyl Estradiol; Norgestrel: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Ethotoin: (Moderate) Hydantoin anticonvulsants can theoretically add to the CNS-depressant effects of other CNS depressants. Also, hepatic enzyme inducers such as hydantoins can theoretically increase the clearance of clonazepam.
    Etomidate: (Moderate) Concomitant administration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent.
    Fedratinib: (Moderate) Monitor for increased sedation and respiratory depression if clonazepam is coadministered with fedratinib; adjust the dose of clonazepam if necessary. The systemic exposure of clonazepam may be increased resulting in an increase in treatment-related adverse reactions. Fedratinib is a moderate CYP3A4 inhibitor and clonazepam is a CYP3A4 substrate.
    Fentanyl: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Fluconazole: (Moderate) Use fluconazole cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam in a CYP3A4 substrate. Fluconazole is a CYP3A4 inhibitor.
    Flumazenil: (Major) Flumazenil competes with benzodiazepines for binding at the GABA/benzodiazepine-receptor complex, the specific binding site of benzodiazepines. Because binding at the receptor is competitive and flumazenil has a much shorter duration of action than do most benzodiazepines, it is possible for the effects of flumazenil to dissipate sooner than the effects of the benzodiazepine. Flumazenil does not affect the pharmacokinetics of the benzodiazepines. Abrupt awakening can cause dysphoria, agitation, and possibly increased adverse effects. If administered to patients who have received a benzodiazepine chronically, abrupt interruption of benzodiazepine agonism by flumazenil can induce benzodiazepine withdrawal including seizures. Flumazenil has minimal effects on benzodiazepine-induced respiratory depression; suitable ventilatory support should be available, especially in treating acute benzodiazepine overdose. Flumazenil does not reverse the actions of barbiturates, opiate agonists, or tricyclic antidepressants.
    Fluoxetine: (Moderate) Fluoxetine may inhibit CYP3A4 metabolism of oxidized benzodiazepines, including clonazepam. Patients should be monitored for clinical response, and adjust benzodiazepine dosage if needed.
    Fluoxetine; Olanzapine: (Moderate) Although oral formulations of olanzapine and benzodiazepines may be used together, additive effects on respiratory depression and/or CNS depression are possible. Drugs that can cause CNS depression, if used concomitantly with olanzapine, can increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, dizziness, and orthostatic hypotension. Besides ethanol, clinicians should use other anxiolytics, sedatives, and hypnotics cautiously with olanzapine. (Moderate) Fluoxetine may inhibit CYP3A4 metabolism of oxidized benzodiazepines, including clonazepam. Patients should be monitored for clinical response, and adjust benzodiazepine dosage if needed.
    Fluvoxamine: (Moderate) Clonazepam is a substrate of CYP3A4. In theory, co-administration of clonazepam and a potent CYP3A4 inhibitor, such as fluvoxamine, may reduce the metabolism of clonazepam and increase the potential for benzodiazepine toxicity. Fluoxetine, another CYP3A4 inhibitor, does not affect the pharmacokinetics of clonazepam. Monitor patients closely for excessive clonazepam side effects, including changes in psychomotor performance and sedation.
    Food: (Major) Coadministration of marijuana with benzodiazepines may result in an exaggerated sedative effect. Instruct patients receiving these medications concurrently not to drive or operate machinery.
    Fosamprenavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Fosphenytoin: (Moderate) Closely monitor for loss of seizure control, increased anxiety, or panic attacks if clonazepam and fosphenytoin, a prodrug of phenytoin, are used concurrently. Monitoring of phenytoin serum concentrations is recommended. Monitor for increased adverse effects from phenytoin, such as nystagmus, ataxia, slurred speech, nausea, vomiting, confusion, or lethargy. The metabolism of clonazepam by CYP3A4 may be induced by phenytoin resulting in decreased clonazepam concentrations. Clonazepam is a CYP3A4 substrate, and phenytoin is a strong CYP3A4 inducer. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam was used with potent CYP3A4 inducers. The effect of the interaction on phenytoin concentrations is unpredictable, and the mechanism of interaction is unclear. In 1 case report, phenytoin concentrations decreased approximately 28% when clonazepam was added to phenytoin therapy in an epileptic patient and a corresponding increase in seizures was seen. In a study that assessed the effect of clonazepam on phenytoin plasma concentrations, 9 patients experienced increased phenytoin concentrations when clonazepam was introduced. The magnitude of concentration increase is not reported. Phenytoin concentrations decreased in 1 patient and remained unchanged in 3 patients when clonazepam was introduced. It is unclear if the concentration increases were due to a drug interaction or increased compliance with phenytoin therapy.
    Fospropofol: (Moderate) Concomitant administration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent.
    General anesthetics: (Moderate) Concomitant administration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent.
    Green Tea: (Minor) Patients taking benzodiazepines for insomnia should not use caffeine-containing products, such as green tea, prior to going to bed as these products may antagonize the sedative effects of the benzodiazepine.
    Guaifenesin; Hydrocodone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines.
    Guaifenesin; Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines.
    Guaifenesin; Phenylephrine: (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Guanabenz: (Moderate) Guanabenz is associated with sedative effects. Guanabenz can potentiate the effects of CNS depressants such as benzodiazepines, when administered concomitantly.
    Guanfacine: (Moderate) Guanfacine has been associated with sedative effects and can potentiate the actions of other CNS depressants including benzodiazepines.
    Haloperidol: (Moderate) Haloperidol can potentiate the actions of other CNS depressants, such as benzodiazepines, Caution should be exercised with simultaneous use of these agents due to potential excessive CNS effects.
    Halothane: (Moderate) Concomitant administration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent.
    Homatropine; Hydrocodone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines.
    Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Methyldopa is associated with sedative effects. Methyldopa can potentiate the effects of CNS depressants such as barbiturates, benzodiazepines, opiate agonists, or phenothiazines when administered concomitantly.
    Hydrocodone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines.
    Hydrocodone; Ibuprofen: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines.
    Hydrocodone; Phenylephrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines. (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Hydrocodone; Potassium Guaiacolsulfonate: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines.
    Hydrocodone; Potassium Guaiacolsulfonate; Pseudoephedrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines.
    Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydrocodone is initiated in a patient taking a benzodiazepine, reduce initial dosage and titrate to clinical response; for hydrocodone extended-release products, initiate hydrocodone at 20% to 30% of the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines.
    Hydromorphone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If hydromorphone is initiated in a patient taking a benzodiazepine, reduce the initial dosage of hydromorphone and titrate to clinical response; for hydromorphone extended-release tablets, use 1/3 to 1/2 of the estimated hydromorphone starting dose. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Hydroxychloroquine: (Moderate) Caution is warranted with the coadministration of hydroxychloroquine and antiepileptic drugs, such as clonazepam. Hydroxychloroquine can lower the seizure threshold; therefore, the activity of antiepileptic drugs may be impaired with concomitant use.
    Hydroxyzine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Ibuprofen; Oxycodone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If oxycodone is initiated in a patient taking a benzodiazepine, reduce dosages and titrate to clinical response. For acetaminophen; oxycodone extended-release tablets, start with 1 tablet PO every 12 hours, and for other oxycodone products, use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Idelalisib: (Major) Avoid concomitant use of idelalisib, a strong CYP3A inhibitor, with clonazepam, a CYP3A substrate, as clonazepam toxicities may be significantly increased. The AUC of a sensitive CYP3A substrate was increased 5.4-fold when coadministered with idelalisib.
    Iloperidone: (Moderate) Drugs that can cause CNS depression, if used concomitantly with iloperidone, may increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, and dizziness. Caution should be used when iloperidone is given in combination with other centrally-acting medications including anxiolytics, sedatives, and hypnotics.
    Imatinib: (Moderate) CYP3A4 inhibitors, such as imatinib, may reduce the metabolism of clonazepam and increase the potential for benzodiazepine toxicity.
    Indinavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Iohexol: (Moderate) The use of intrathecal radiopaque contrast agents is associated with a risk of seizures. Patients should be instructed to continue using benzodiazepines during procedures or exams that require the use of intrathecal radiopaque contrast agents as abrupt discontinuation of benzodiazepines may also increase seizure risk.
    Iopamidol: (Moderate) The use of intrathecal radiopaque contrast agents is associated with a risk of seizures. Patients should be instructed to continue using benzodiazepines during procedures or exams that require the use of intrathecal radiopaque contrast agents as abrupt discontinuation of benzodiazepines may also increase seizure risk.
    Isavuconazonium: (Moderate) Use isavuconazonium cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Isavuconazole, the active moiety of isavuconazonium, is a CYP3A4 inhibitor.
    Isoflurane: (Moderate) Concomitant administration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent.
    Isoniazid, INH: (Moderate) Isoniazid, INH can decrease the hepatic oxidative metabolism of clonazepam if administered concomitantly. Monitor for signs of an exaggerated response to clonazepam if isoniazid is used concomitantly.
    Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Moderate) Isoniazid, INH can decrease the hepatic oxidative metabolism of clonazepam if administered concomitantly. Monitor for signs of an exaggerated response to clonazepam if isoniazid is used concomitantly. (Moderate) Monitor patients for a change in clonazepam dosage requirements when starting or stopping concomitant rifampin. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Rifampin is a strong CYP3A4 inducer.
    Isoniazid, INH; Rifampin: (Moderate) Isoniazid, INH can decrease the hepatic oxidative metabolism of clonazepam if administered concomitantly. Monitor for signs of an exaggerated response to clonazepam if isoniazid is used concomitantly. (Moderate) Monitor patients for a change in clonazepam dosage requirements when starting or stopping concomitant rifampin. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Rifampin is a strong CYP3A4 inducer.
    Itraconazole: (Moderate) Use itraconazole cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Itraconazole is a strong CYP3A4 inhibitor.
    Kava Kava, Piper methysticum: (Major) Kava kava should be avoided when possible in patients taking benzodiazepines. Additive sedation or other CNS-related side effects are possible. Kava may inhibit CYP enzymes, increasing benzodiazepine exposure, which may increase the risk for CNS depression and respiratory compromise. Patients should discuss the use of herbal supplements with their health care professional prior to consuming kava kava and should not abruptly stop taking their prescribed medications.
    Ketamine: (Moderate) Concomitant administration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent.
    Ketoconazole: (Moderate) Use ketoconazole cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Ketoconazole is a strong CYP3A4 inhibitor.
    Lefamulin: (Moderate) Monitor for increased sedation and respiratory depression if clonazepam is coadministered with oral lefamulin; adjust the dose of clonazepam if necessary. The systemic exposure of clonazepam may be increased resulting in an increase in treatment-related adverse reactions. Clonazepam is a CYP3A4 substrate and oral lefamulin is a moderate CYP3A4 inhibitor; an interaction is not expected with intravenous lefamulin.
    Lesinurad: (Moderate) Lesinurad may decrease the systemic exposure and therapeutic efficacy of clonazepam; monitor for potential reduction in efficacy. Clonazepam is a CYP3A substrate, and lesinurad is a weak CYP3A inducer.
    Lesinurad; Allopurinol: (Moderate) Lesinurad may decrease the systemic exposure and therapeutic efficacy of clonazepam; monitor for potential reduction in efficacy. Clonazepam is a CYP3A substrate, and lesinurad is a weak CYP3A inducer.
    Letermovir: (Moderate) A clinically relevant increase in the plasma concentration of clonazepam may occur if given with letermovir. In patients who are also receiving treatment with cyclosporine, the magnitude of this interaction may be amplified. Clonazepam is a CYP3A4 substrate. Letermovir is a moderate CYP3A4 inhibitor; however, when given with cyclosporine, the combined effect on CYP3A4 substrates is similar to a strong CYP3A4 inhibitor.
    Levocetirizine: (Moderate) Concurrent use of cetirizine/levocetirizine with benzodiazepines should generally be avoided. Coadministration may increase the risk of CNS depressant-related side effects. If concurrent use is necessary, monitor for excessive sedation and somnolence.
    Levomethadyl: (Moderate) Concomitant administration of benzodiazepines with CNS-depressant drugs, including opiate agonists, can potentiate the CNS effects of either agent.
    Levomilnacipran: (Moderate) Concurrent use of many CNS active drugs, including benzodiazepines, with levomilnacipran has not been evaluated by the manufacturer. Therefore, caution is advisable when combining anxiolytics, sedatives, and hypnotics or other psychoactive medications with levomilnacipran.
    Levorphanol: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If levorphanol is initiated in a patient taking a benzodiazepine, reduce the initial dose of levorphanol by approximately 50% or more. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Lisdexamfetamine: (Moderate) Patients who are taking anticonvulsants for epilepsy/seizure control should use lisdexamfetamine with caution. Amphetamines may decrease the seizure threshold and may increase the risk of seizures. If seizures occur, amphetamine discontinuation may be necessary.
    Lithium: (Moderate) Because lithium has the potential to impair cognitive and motor skills, caution is advisable during concurrent use of other medications with centrally-acting effects including anxiolytics, sedatives, and hypnotics.
    Lofexidine: (Moderate) Monitor for excessive hypotension and sedation during coadministration of lofexidine and benzodiazepines. Lofexidine can potentiate the effects of CNS depressants such as benzodiazepines.
    Lopinavir; Ritonavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Lumacaftor; Ivacaftor: (Moderate) Lumacaftor may induce the metabolism of clonazepam thereby decreasing the systemic exposure and therapeutic effect. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Lumacaftor is a strong CYP3A4 inducer.
    Lurasidone: (Moderate) Due to the CNS effects of lurasidone, caution should be used when lurasidone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics, including benzodiazepines. In one study, co-administration of lurasidone and midazolam increased the Cmax and AUC of midazolam by about 21% and 44%, respectively, compared to midazolam alone; however, dosage adjustment of midazolam based upon pharmacokinetic parameters is not required during concurrent use of lurasidone.
    Magnesium Salts: (Minor) Because of the CNS-depressant effects of magnesium sulfate, additive central-depressant effects can occur following concurrent administration with CNS depressants such as benzodiazepines. Caution should be exercised when using these agents concurrently.
    Maprotiline: (Moderate) Benzodiazepines or other CNS depressants should be combined cautiously with maprotiline because they could cause additive depressant effects and possible respiratory depression or hypotension. The combination of benzodiazepines and maprotiline is commonly used clinically and is considered to be safe as long as patients are monitored for excessive adverse effects from either agent. Maprotiline may lower the seizure threshold, so when benzodiazepines are used for anticonvulsant effects the patient should be monitored for desired clinical outcomes.
    Meclizine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Mefloquine: (Moderate) Coadministration of mefloquine and anticonvulsants may result in lower than expected anticonvulsant concentrations and loss of seizure control. Monitoring of the anticonvulsant serum concentration is recommended. Dosage adjustments may be required during and after therapy with mefloquine.
    Melatonin: (Major) Use caution when combining melatonin with the benzodiazepines; when the benzodiazepine is used for sleep, co-use of melatonin should be avoided. In animal studies, melatonin has been shown to increase benzodiazepine binding to receptor sites. In one case report, a benzodiazepine-dependent woman with an 11 year history of insomnia weaned and discontinued her benzodiazepine prescription within a few days without rebound insomnia or apparent benzodiazepine withdrawal when melatonin was given. In another case report, the ingestion of excessive melatonin along with normal doses of chlordiazepoxide and an antidepressant resulted in lethargy and short-term amnestic responses. Both cases suggest additive pharmacodynamic effects. In a clinical trial, there was clear evidence for a transitory pharmacodynamic interaction between melatonin and another hypnotic agent one hour following co-dosing. Concomitant administration resulted in increased impairment of attention, memory and coordination compared to the hypnotic agent alone. Use of more than one agent for hypnotic purposes may increase the risk for over-sedation, CNS effects, or sleep-related behaviors. Be alert for unusual changes in moods or behaviors.Patients reporting unusual sleep-related behaviors likely should discontinue melatonin use.
    Meperidine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Meperidine; Promethazine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Mephobarbital: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Meprobamate: (Moderate) Concomitant administration of benzodiazepines with meprobamate can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. If used together, a reduction in the dose of one or both drugs may be needed.
    Mestranol; Norethindrone: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Methadone: (Major) Concurrent use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective dose and minimum duration possible. If methadone is initiated for pain in an opioid-naive patient taking a benzodiazepine, use an initial methadone dose of 2.5 mg PO every 12 hours. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial benzodiazepine dose and titrate to response. In patients treated with methadone for opioid use disorder, cessation of benzodiazepines or other CNS depressants is preferred in most cases. Consider alternatives to benzodiazepines for conditions such as anxiety or insomnia during methadone maintenance treatment. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Methocarbamol: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including skeletal muscle relaxants, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Methohexital: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Methscopolamine: (Moderate) CNS depression can be increased when methscopolamine is combined with other CNS depressants such as any anxiolytics, sedatives, and hypnotics.
    Methyldopa: (Moderate) Methyldopa is associated with sedative effects. Methyldopa can potentiate the effects of CNS depressants such as barbiturates, benzodiazepines, opiate agonists, or phenothiazines when administered concomitantly.
    Metoclopramide: (Minor) Combined use of metoclopramide and other CNS depressants, such as anxiolytics, sedatives, and hypnotics, can increase possible sedation.
    Metyrapone: (Moderate) Metyrapone may cause dizziness and/or drowsiness. Other drugs that may also cause drowsiness, such as benzodiazepines, should be used with caution. Additive drowsiness and/or dizziness is possible.
    Metyrosine: (Moderate) The concomitant administration of metyrosine with benzodiazepines can result in additive sedative effects.
    Mifepristone: (Moderate) Use mifepristone cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Mifepristone is a CYP3A4 inhibitor.
    Milnacipran: (Moderate) Concurrent use of many CNS-active drugs with milnacipran or levomilnacipran has not been evaluated by the manufacturer. Therefore, caution is advisable when combining anxiolytics, sedatives, and hypnotics or other psychoactive medications with these medications.
    Minocycline: (Minor) Injectable minocycline contains magnesium sulfate heptahydrate. Because of the CNS-depressant effects of magnesium sulfate, additive central-depressant effects can occur following concurrent administration with CNS depressants such as benzodiazepines. Caution should be exercised when using these agents concurrently.
    Mirtazapine: (Moderate) Consistent with the pharmacology of mirtazapine and the drug's side effect profile, additive effects may occur with other CNS-active agents, including benzodiazepines.
    Mitotane: (Moderate) Monitor patients for a change in clonazepam dosage requirements when giving concurrently with mitotane. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Mitotane is a strong CYP3A4 inducer.
    Mivacurium: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Molindone: (Moderate) Consistent with the pharmacology of molindone, additive effects may occur with other CNS active drugs such as anticonvulsants. In addition, seizures have been reported during the use of molindone, which is of particular significance in patients with a seizure disorder receiving anticonvulsants. Adequate dosages of anticonvulsants should be continued when molindone is added; patients should be monitored for clinical evidence of loss of seizure control or the need for dosage adjustments of either molindone or the anticonvulsant.
    Monoamine oxidase inhibitors: (Moderate) The CNS-depressant effects of MAOIs can be potentiated with concomitant administration of other drugs known to cause CNS depression including benzodiazepines. MAOIs can cause a variable change in seizure patterns, so careful monitoring of the patient with epilepsy is required when benzodiazepines are used in the treatment of epilepsy.
    Morphine: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If morphine is initiated in a patient taking a benzodiazepine, reduce initial dosages and titrate to clinical response. For extended-release tablets, start with morphine 15 mg PO every 12 hours, and for extended-release capsules, start with 30 mg PO every 24 hours or less. Use an initial morphine; naltrexone dose of 20 mg/0.8 mg PO every 24 hours. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Morphine; Naltrexone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If morphine is initiated in a patient taking a benzodiazepine, reduce initial dosages and titrate to clinical response. For extended-release tablets, start with morphine 15 mg PO every 12 hours, and for extended-release capsules, start with 30 mg PO every 24 hours or less. Use an initial morphine; naltrexone dose of 20 mg/0.8 mg PO every 24 hours. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Nabilone: (Moderate) Concomitant use of nabilone with other CNS depressants can potentiate the effects of nabilone on respiratory depression.
    Nalbuphine: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Nefazodone: (Moderate) Use nefazodone cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Nefazodone is a CYP3A4 inhibitor.
    Nelfinavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Neuromuscular blockers: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Nevirapine: (Moderate) Nevirapine may induce the metabolism of certain benzodiazepines that are metabolized through the cytochrome P450 system, including clonazepam.
    Nicardipine: (Moderate) CYP3A4 inhibitors, such as nicardipine, may reduce the metabolism of clonazepam and increase the potential for benzodiazepine toxicity. Monitor patients closely who receive concurrent therapy.
    Nilotinib: (Moderate) Concomitant use of nilotinib, a moderate CYP3A4 inhibitor, and clonazepam, a CYP3A4 substrate, may result in increased clonazepam levels. A clonazepam dose reduction may be necessary if these drugs are used together.
    Nitroglycerin: (Minor) Nitroglycerin can cause hypotension. This action may be additive with other agents that can cause hypotension such as benzodiazepines. Patients should be monitored more closely for hypotension if nitroglycerin is used concurrently with benzodiazepines.
    Olanzapine: (Moderate) Although oral formulations of olanzapine and benzodiazepines may be used together, additive effects on respiratory depression and/or CNS depression are possible. Drugs that can cause CNS depression, if used concomitantly with olanzapine, can increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, dizziness, and orthostatic hypotension. Besides ethanol, clinicians should use other anxiolytics, sedatives, and hypnotics cautiously with olanzapine.
    Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Omeprazole: (Moderate) Omeprazole inhibits CYP2C19. There have been some case reports describing an interaction between omeprazole and benzodiazepines metabolized via the cytochrome P450 system, such as clonazepam. Patients should be monitored to determine if it is necessary to adjust the dosage of the benzodiazepine when taken concomitantly with omeprazole.
    Omeprazole; Sodium Bicarbonate: (Moderate) Omeprazole inhibits CYP2C19. There have been some case reports describing an interaction between omeprazole and benzodiazepines metabolized via the cytochrome P450 system, such as clonazepam. Patients should be monitored to determine if it is necessary to adjust the dosage of the benzodiazepine when taken concomitantly with omeprazole.
    Oritavancin: (Moderate) Clonazepam is metabolized by CYP3A4; oritavancin is a weak CYP3A4 inducer. Plasma concentrations and efficacy of clonazepam may be reduced if these drugs are administered concurrently.
    Oxybutynin: (Moderate) Additive CNS depression may occur when oxybutynin is used concomitantly with other CNS-depressant drugs, including anxiolytics, sedatives, and hypnotics.
    Oxycodone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If oxycodone is initiated in a patient taking a benzodiazepine, reduce dosages and titrate to clinical response. For acetaminophen; oxycodone extended-release tablets, start with 1 tablet PO every 12 hours, and for other oxycodone products, use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Oxymorphone: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If oxymorphone is initiated in a patient taking a benzodiazepine, use an initial dose of oxymorphone at 1/3 to 1/2 the usual dosage and titrate to clinical response. If the extended-release oxymorphone tablets are used concurrently with a CNS depressant, use an initial dosage of 5 mg PO every 12 hours. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Paliperidone: (Moderate) Drugs that can cause CNS depression, such as benzodiazepines, can increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, and dizziness when coadministered with paliperidone. Monitor for signs and symptoms of CNS depression and advise patients to avoid driving or engaging in other activities requiring mental alertness until they know how this combination affects them.
    Pancuronium: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Papaverine: (Moderate) Concurrent use of papaverine with potent CNS depressants such as benzodiazepines could lead to enhanced sedation.
    Pazopanib: (Moderate) Pazopanib is a weak inhibitor of CYP3A4. Coadministration of pazopanib and clonazepam, a CYP3A4 substrate, may cause an increase in systemic concentrations of clonazepam. Use caution when administering these drugs concomitantly.
    Pemoline: (Moderate) A reduction in seizure threshold has been reported following concomitant administration of pemoline with anticonvulsant agents.
    Pentazocine: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Pentazocine; Naloxone: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Pentobarbital: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Perampanel: (Moderate) Patients taking benzodiazepines with perampanel may experience increased CNS depression. Monitor patients for adverse effects; dose adjustment of either drug may be necessary. Use of midazolam in healthy subjects who received perampanel 6 mg once daily for 20 days decreased the AUC and Cmax of midazolam by 13% and 15%, respectively, possibly due to weak induction of CYP3A4 by perampanel; the specific clinical significance of this interaction is unknown.
    Phenobarbital: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Phenothiazines: (Moderate) Phenothiazines are CNS depressant drugs that may have cumulative effects when administered concurrently and they should be used cautiously with anxiolytic, sedative, and hypnotic type drugs, such as the benzodiazepines. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension. Additionally, sleep-related behaviors, such as sleep-driving, are more likely to occur during concurrent use of other CNS depressants than with sedatives alone. Monitor for additive effects, unusual moods or behaviors, and warn about the potential effects to driving and other activities.
    Phentermine; Topiramate: (Moderate) Topiramate has the potential to cause CNS depression as well as other cognitive and/or neuropsychiatric adverse reactions. The CNS depressant effects of topiramate can be potentiated pharmacodynamically by concurrent use of CNS depressant agents such as the benzodiazepines. Concurrent use of topiramate and benzodiazepines associated with thrombocytopenia (e.g., clonazepam, lorazepam, and clobazam), may also increase the risk of bleeding; monitor patients appropriately during benzodiazepine therapy.
    Phenylephrine: (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Phenylephrine; Promethazine: (Moderate) The therapeutic effect of phenylephrine may be decreased in patients receiving benzodiazepines. Monitor patients for decreased pressor effect if these agents are administered concomitantly.
    Phenytoin: (Moderate) Monitor phenytoin concentrations during coadministration with clonazepam. Clonazepam has the potential to influence phenytoin concentrations. In a case report, an epileptic patient experienced a decrease in phenytoin concentrations by approximately 28%, which coincided with an increase in seizures. In a study that assessed the effect of clonazepam on phenytoin plasma concentrations, 9 patients experienced increased phenytoin concentrations when clonazepam was introduced. The magnitude of concentration increase is not reported. Phenytoin concentrations decreased in 1 patient and remained unchanged in 3 patients when clonazepam was introduced. It is unclear if the concentration increases were due to a drug interaction or increased compliance with phenytoin therapy. Also, clonazepam concentration decreases of approximately 38% have been reported when clonazepam, a CYP3A4 substrate, is used with strong CYP3A4 inducers, like phenytoin.
    Pimozide: (Moderate) Due to the effects of pimozide on cognition, it should be used cautiously with other CNS depressants including benzodiazepines.
    Posaconazole: (Moderate) Use posaconazole cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Posaconazole is a strong CYP3A4 inhibitor.
    Pramipexole: (Major) Concomitant administration of benzodiazepines with CNS-depressant drugs, including pramipexole, can potentiate the CNS effects.
    Prasterone, Dehydroepiandrosterone, DHEA (Dietary Supplements): (Major) Prasterone, dehydroepiandrosterone, DHEA may inhibit the metabolism of benzodiazepines (e.g., alprazolam, estazolam, midazolam) which undergo CYP3A4-mediated metabolism. In one study of elderly volunteers, half of the patients received DHEA 200 mg/day PO for 2 weeks, followed by a single dose of triazolam 0.25 mg. Triazolam clearance was reduced by close to 30% in the DHEA-pretreated patients vs. the control group; however, the effect of DHEA on CYP3A4 metabolism appeared to vary widely among subjects. While more study is needed, benzodiazepine-induced CNS sedation and other adverse effects might be increased in some individuals if DHEA is co-administered.
    Prasterone, Dehydroepiandrosterone, DHEA (FDA-approved): (Major) Prasterone, dehydroepiandrosterone, DHEA may inhibit the metabolism of benzodiazepines (e.g., alprazolam, estazolam, midazolam) which undergo CYP3A4-mediated metabolism. In one study of elderly volunteers, half of the patients received DHEA 200 mg/day PO for 2 weeks, followed by a single dose of triazolam 0.25 mg. Triazolam clearance was reduced by close to 30% in the DHEA-pretreated patients vs. the control group; however, the effect of DHEA on CYP3A4 metabolism appeared to vary widely among subjects. While more study is needed, benzodiazepine-induced CNS sedation and other adverse effects might be increased in some individuals if DHEA is co-administered.
    Pregabalin: (Moderate) Pregabalin can potentiate the CNS-depressant action of other drugs such as benzodiazepines. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
    Primidone: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Probenecid: (Moderate) Probenecid may inhibit the metabolism of the benzodiazepines, including those which are metabolized by conjugation (e.g., lorazepam) or oxidation (e.g., midazolam). Probenecid has been shown to decrease lorazepam clearance by about 50% and increase its elimination half-life. In addition, pretreatment with probenecid shortened the induction time (85 vs. 109 seconds) of midazolam in presurgical patients. Patients receiving alprazolam therapy should be monitored for signs of altered benzodiazepine response when probenecid is initiated or discontinued.
    Procarbazine: (Minor) CNS depressants benzodiazepines can potentiate the CNS depression caused by procarbazine therapy, so these drugs should be used together cautiously.
    Propofol: (Moderate) Concomitant administration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent.
    Propoxyphene: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. The dose of any opiate agonist administered with parenteral diazepam should be reduced by at least one-third.
    Protease inhibitors: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Quetiapine: (Moderate) Somnolence is a commonly reported adverse effect of quetiapine; coadministration of quetiapine with anxiolytics, sedatives, and hypnotics, or other CNS depressants may result in additive sedative effects.
    Ramelteon: (Moderate) Ramelteon is a sleep-promoting agent; therefore, additive pharmacodynamic effects are possible when combining ramelteon with benzodiazepines or other miscellaneous anxiolytics, sedatives, and hypnotics. Pharmacokinetic interactions have been observed with the use of zolpidem. Use of ramelteon 8 mg/day for 11 days and a single dose of zolpidem 10 mg resulted in an increase in the median Tmax of zolpidem of about 20 minutes; exposure to zolpidem was unchanged. Ramelteon use with hypnotics of any kind is considered duplicative therapy and these drugs are generally not co-administered.
    Ranolazine: (Moderate) CYP3A4 inhibitors, like ranolazine, may reduce the metabolism of clonazepam and increase the potential for benzodiazepine toxicity.
    Rapacuronium: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Rasagiline: (Moderate) The CNS-depressant effects of MAOIs can be potentiated with concomitant administration of other drugs known to cause CNS depression including buprenorphine, butorphanol, dronabinol, THC, nabilone, nalbuphine, and anxiolytics, sedatives, and hypnotics. Use these drugs cautiously with MAOIs; warn patients to not drive or perform other hazardous activities until they know how a particular drug combination affects them. In some cases, the dosages of the CNS depressants may need to be reduced.
    Remifentanil: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Benzodiazepine doses may need to be reduced up to 75% during coadministration with remifentanil. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Ribociclib: (Moderate) Monitor for an increase in clonazepam-related adverse reactions, including sedation and respiratory depression, if coadministration with ribociclib is necessary. Clonazepam is a CYP3A4 substrate and ribociclib is a strong CYP3A4 inhibitor.
    Ribociclib; Letrozole: (Moderate) Monitor for an increase in clonazepam-related adverse reactions, including sedation and respiratory depression, if coadministration with ribociclib is necessary. Clonazepam is a CYP3A4 substrate and ribociclib is a strong CYP3A4 inhibitor.
    Rifabutin: (Moderate) Rifabutin is a hepatic inducer and can theoretically increase the clearance of benzodiazepines metabolized by oxidative metabolism, such as clonazepam, leading to lower benzodiazepine concentrations.
    Rifampin: (Moderate) Monitor patients for a change in clonazepam dosage requirements when starting or stopping concomitant rifampin. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Rifampin is a strong CYP3A4 inducer.
    Rifapentine: (Moderate) Rifapentine induces hepatic isoenzyme CYP3A4. Drugs metabolized by CYP3A4, such as clonazepam, may require dosage adjustments when administered concurrently with rifapentine.
    Risperidone: (Moderate) Due to the primary CNS effects of risperidone, caution should be used when risperidone is given in combination with other centrally acting medications including anxiolytics, sedatives, and hypnotics.
    Ritonavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Rocuronium: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Rotigotine: (Major) Concomitant use of rotigotine with other CNS depressants, such as benzodiazepines, can potentiate the sedative effects of rotigotine.
    Safinamide: (Moderate) Dopaminergic medications, including safinamide, may cause a sudden onset of somnolence which sometimes has resulted in motor vehicle accidents. Patients may not perceive warning signs, such as excessive drowsiness, or they may report feeling alert immediately prior to the event. Because of possible additive effects, advise patients about the potential for increased somnolence during concurrent use of safinamide with other sedating medications, such as benzodiazepines.
    Saquinavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Scopolamine: (Moderate) Scopolamine may cause dizziness and drowsiness. Concurrent use of scopolamine and CNS depressants can adversely increase the risk of CNS depression.
    Secobarbital: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Sedating H1-blockers: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Segesterone Acetate; Ethinyl Estradiol: (Minor) Oral contraceptives can increase the effects of clonazepam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to clonazepam.
    Sevelamer: (Major) When sevelamer is coadministered with oral drugs considered to have narrow therapeutic ranges (e.g., anticonvulsants), the potential for reduced drug absorption could result in clinical significance, with the potential for loss of efficacy. To minimize this interaction, patients should be advised to separate the administration of anticonvulsants by at least 1 hour before or 3 hours after sevelamer. In addition, patients should be monitored for changes in efficacy of the anticonvulsant when these drugs are coadministered.
    Sevoflurane: (Moderate) Concomitant administration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent.
    Simeprevir: (Moderate) Simeprevir, a mild intestinal CYP3A4 inhibitor, may increase the side effects of clonazepam, which is a CYP3A4 substrate. Monitor patients for adverse effects of clonazepam, such as CNS depression.
    Sincalide: (Moderate) Sincalide-induced gallbladder ejection fraction may be affected by benzodiazepines. False study results are possible in patients with drug-induced hyper- or hypo-responsiveness; thorough patient history is important in the interpretation of procedure results.
    Skeletal Muscle Relaxants: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
    Sodium Oxybate: (Severe) Sodium oxybate should not be used in combination with CNS depressant anxiolytics, sedatives, and hypnotics or other sedative CNS depressant drugs. Specifically, sodium oxybate use is contraindicated in patients being treated with sedative hypnotic drugs. Sodium oxybate (GHB) has the potential to impair cognitive and motor skills. For example, the concomitant use of barbiturates and benzodiazepines increases sleep duration and may contribute to rapid onset, pronounced CNS depression, respiratory depression, or coma when combined with sodium oxybate.
    St. John's Wort, Hypericum perforatum: (Moderate) Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers, like St. John's Wort. Clonazepam is a CYP3A4 substrate.
    Succinylcholine: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Sufentanil: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Suvorexant: (Moderate) CNS depressant drugs may have cumulative effects when administered concurrently and they should be used cautiously with suvorexant. A reduction in dose of the CNS depressant may be needed in some cases. These agents include the benzodiazepines.
    Tapentadol: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If tapentadol is initiated in a patient taking a benzodiazepine, a reduced initial dosage of tapentadol is recommended. If the extended-release tapentadol tablets are used concurrently with a benzodiazepine, use an initial tapentadol dose of 50 mg PO every 12 hours. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Teduglutide: (Moderate) Teduglutide may increase absorption of benzodiazepines or other psychotropic agents because of it's pharmacodynamic effect of improving intestinal absorption. In studies with teduglutide, one of the subjects was receiving concomitant treatment with prazepam and experienced dramatic deterioration in mental status progressing to coma during her first week of teduglutide therapy. Upon admission to the ICU, her benzodiazepine level was reported as >300 mcg/L. Both drugs were discontinued, and the coma resolved 5 days later. Careful monitoring and possible dose adjustment of the psychotropic agent is recommended.
    Telaprevir: (Moderate) Close clinical monitoring is advised when administering clonazepam with telaprevir due to an increased potential for clonazepam-related adverse events. If clonazepam dose adjustments are made, re-adjust the dose upon completion of telaprevir treatment. Although this interaction has not been studied, predictions about the interaction can be made based on the metabolic pathway of clonazepam. Clonazepam is metabolized by the hepatic isoenzyme CYP3A4; telaprevir inhibits this isoenzyme. Coadministration may result in elevated clonazepam plasma concentrations.
    Telithromycin: (Moderate) Use telithromycin cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Telithromycin is a CYP3A4 inhibitor.
    Telotristat Ethyl: (Moderate) Use caution if coadministration of telotristat ethyl and clonazepam is necessary, as the systemic exposure of clonazepam may be decreased resulting in reduced efficacy. If these drugs are used together, monitor patients for suboptimal efficacy of clonazepam; consider increasing the dose of clonazepam if necessary. Clonazepam is a CYP3A4 substrate. The mean Cmax and AUC of another sensitive CYP3A4 substrate was decreased by 25% and 48%, respectively, when coadministered with telotristat ethyl; the mechanism of this interaction appears to be that telotristat ethyl increases the glucuronidation of the CYP3A4 substrate.
    Tetrabenazine: (Moderate) Concurrent use of tetrabenazine and drugs that can cause CNS depression, such as benzodiazepines, can increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, dizziness, and orthostatic hypotension.
    Thalidomide: (Major) The use of benzodiazepine anxiolytics, sedatives, or hypnotics with thalidomide may cause an additive sedative effect and should be avoided. Thalidomide frequently causes drowsiness and somnolence. Dose reductions may be required. Patients should be instructed to avoid situations where drowsiness may be a problem and not to take other medications that may cause drowsiness without adequate medical advice. Advise patients as to the possible impairment of mental and/or physical abilities required for the performance of hazardous tasks, such as driving a car or operating other complex or dangerous machinery.
    Theophylline, Aminophylline: (Moderate) Aminophylline has been reported to counteract the pharmacodynamic effects of diazepam. A proposed mechanism is competitive binding of aminophylline to adenosine receptors in the brain. Whether a similar interaction occurs with other benzodiazepines is not known. If aminophylline therapy is initiated or discontinued, monitor the clinical response to benzodiazepines. (Moderate) Theophylline has been reported to counteract the pharmacodynamic effects of diazepam. A proposed mechanism is competitive binding of theophylline to adenosine receptors in the brain. Whether a similar interaction occurs with other benzodiazepines is not known. If theophylline therapy is initiated or discontinued, monitor the clinical response to benzodiazepines.
    Thiopental: (Moderate) Monitoring of clonazepam concentrations or dosage adjustment may be necessary if used concurrently with barbiturates due to decreased clonazepam concentrations. Clonazepam concentration decreases of approximately 38% have been reported when clonazepam is used with strong CYP3A4 inducers. Clonazepam is a CYP3A4 substrate. Barbiturates are strong CYP3A4 inducers. Additive CNS and/or respiratory depression may also occur.
    Thiothixene: (Moderate) Thiothixene can potentiate the CNS-depressant action of other drugs such as benzodiazepines. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
    Tiagabine: (Moderate) Because of the possible additive effects of drugs that depress the central nervous system, benzodiazepines should be used with caution in patients receiving tiagabine.
    Tipranavir: (Moderate) Use protease inhibitors cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Protease inhibitors are CYP3A4 inhibitors.
    Tizanidine: (Moderate) Concurrent use of tizanidine and CNS depressants like the benzodiazepines can cause additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
    Topiramate: (Moderate) Topiramate has the potential to cause CNS depression as well as other cognitive and/or neuropsychiatric adverse reactions. The CNS depressant effects of topiramate can be potentiated pharmacodynamically by concurrent use of CNS depressant agents such as the benzodiazepines. Concurrent use of topiramate and benzodiazepines associated with thrombocytopenia (e.g., clonazepam, lorazepam, and clobazam), may also increase the risk of bleeding; monitor patients appropriately during benzodiazepine therapy.
    Tramadol: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Trandolapril; Verapamil: (Moderate) CYP3A4 inhibitors, such as verapamil, may reduce the metabolism of clonazepam and increase the potential for benzodiazepine toxicity.
    Trazodone: (Major) Monitor for excessive sedation and somnolence during coadministration of trazodone and benzodiazepines. Concurrent use may result in additive CNS depression.
    Tricyclic antidepressants: (Moderate) Concomitant administration of benzodiazepines with CNS-depressant drugs, such as tricyclic antidepressants, can potentiate the CNS effects of either agent. Tricyclic antidepressants may also lower the seizure threshold leading to pharmacodynamic interactions with anticonvulsant benzodiazepines (i.e., clobazam, clonazepam, diazepam, and lorazepam). The plasma concentrations of imipramine and desipramine may increase an average of 31% and 20%, respectively, when administered concurrently with alprazolam. The significance of this interaction has not been described; therefore, patients should be monitored closely for symptoms of tricyclic toxicity during coadministration of these agents with alprazolam.
    Trihexyphenidyl: (Moderate) CNS depressants, such as anxiolytics, sedatives, and hypnotics, can increase the sedative effects of trihexyphenidyl.
    Trimethobenzamide: (Moderate) The concurrent use of trimethobenzamide with other medications that cause CNS depression, like the benzodiazepines, may potentiate the effects of either trimethobenzamide or the benzodiazepine.
    Triprolidine: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
    Tubocurarine: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Valerian, Valeriana officinalis: (Major) Any substances that act on the CNS, including psychoactive drugs and drugs used as anesthetic adjuvants (e.g., barbiturates, benzodiazepines), may theoretically interact with valerian, Valeriana officinalis. The valerian derivative, dihydrovaltrate, binds at barbiturate binding sites; valerenic acid has been shown to inhibit enzyme-induced breakdown of GABA in the brain; the non-volatile monoterpenes (valepotriates) have sedative activity. These interactions are probably pharmacodynamic in nature. There is a possibility of interaction with valerian at normal prescription dosages of anxiolytics, sedatives, and hypnotics (including barbiturates and benzodiazepines). Patients who are taking barbiturates or other sedative/hypnotic drugs should avoid concomitant administration of valerian. Patients taking medications such as tricyclic antidepressants, lithium, MAOIs, skeletal muscle relaxants, SSRIs and serotonin norepinephrine reuptake inhibitors (e.g., duloxetine, venlafaxine) should discuss the use of herbal supplements with their health care professional prior to consuming valerian; combinations should be approached with caution in the absence of clinical data. Patients should not abruptly stop taking their prescribed psychoactive medications.
    Valproic Acid, Divalproex Sodium: (Moderate) Although concomitant use of clonazepam and valproic acid has been reported to produce absence status, this combination also has been used successfully in treating refractory seizures in children. This combination should be used only when the benefits outweigh the risks.
    Vecuronium: (Moderate) Concurrent use of benzodiazepines and other CNS active medications including neuromuscular blockers, can potentiate the CNS effects of either agent. Lower doses of one or both agents may be required. The severity of this interaction may be increased when additional CNS depressants are given.
    Vemurafenib: (Moderate) Vemurafenib is an inducer of CYP3A4 and decreased plasma concentrations of drugs metabolized by this enzyme, such as clonazepam, could be expected with concurrent use. Use caution, and monitor therapeutic effects of clonazepam when coadministered with vemurafenib.
    Verapamil: (Moderate) CYP3A4 inhibitors, such as verapamil, may reduce the metabolism of clonazepam and increase the potential for benzodiazepine toxicity.
    Vigabatrin: (Moderate) Vigabatrin may cause somnolence and fatigue. Drugs that can cause CNS depression, if used concomitantly with vigabatrin, may increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, and dizziness. Caution should be used when vigabatrin is given in combination with benzodiazepines.
    Vilazodone: (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.
    Voriconazole: (Moderate) Use voriconazole cautiously and carefully monitor patients receiving concurrent clonazepam due to impaired metabolism of clonazepam leading to exaggerated concentrations and adverse effects, such as CNS and/or respiratory depression. Clonazepam is a CYP3A4 substrate. Voriconazole is a strong CYP3A4 inhibitor.
    Zafirlukast: (Moderate) In vitro data indicate that zafirlukast inhibits the CYP2C9 and CYP3A4 isoenzymes at concentrations close to the clinically achieved total plasma concentrations. Until more clinical data are available, zafirlukast should be used cautiously in patients stabilized on drugs metabolized by CYP3A4, such as clonazepam.
    Zaleplon: (Moderate) In premarketing studies, zaleplon potentiated the CNS effects of ethanol, imipramine, and thioridazine for at least 2 to 4 hours. Other drugs that may have additive CNS effects with zaleplon but have not been studied include benzodiazepines. If used together, a reduction in the dose of one or both drugs may be needed.
    Zileuton: (Moderate) Zileuton is a CYP3A4 inhibitor and may reduce the metabolism of clonazepam and increase the potential for benzodiazepine toxicity.
    Ziprasidone: (Moderate) Ziprasidone has the potential to impair cognitive and motor skills. Additive CNS depressant effects are possible when ziprasidone is used concurrently with any CNS depressant.
    Zolpidem: (Moderate) Concomitant administration of benzodiazepines with zolpidem can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. If used together, a reduction in the dose of one or both drugs may be needed. For Intermezzo brand of sublingual zolpidem tablets, reduce the dose to 1.75 mg/night. Concurrent use of zolpidem with other sedative-hypnotics, including other zolpidem products, at bedtime or the middle of the night is not recommended. In addition, sleep-related behaviors, such as sleep-driving, are more likely to occur during concurrent use of zolpidem and other CNS depressants than with zolpidem alone.

    PREGNANCY AND LACTATION

    Pregnancy

    Avoid prolonged use of clonazepam during breast-feeding, and consider alternative shorter-acting drugs, such as lorazepam. Clonazepam is excreted in breast milk in low concentrations with a milk to plasma ratio of approximately 0.3. However, drug accumulation may occur in the infant due to a long half-life. Sedative effects in the infant, with resultant poor feeding, have been occasionally reported with maternal use of clonazepam. Observational studies suggest that benzodiazepine use, including the use of clonazepam, does not prohibit the initiation of breast-feeding, and that continued maternal use may ensue with close monitoring of the breast-fed infant for sedation, poor feeding, problems with weight gain, and apnea; however, more study is needed. Previous American Academy of Pediatrics (AAP) recommendations considered benzodiazepines to be drugs whose effect on the nursing infant is not known but may be of concern, particularly with prolonged exposure. Consider the developmental and health benefits of breast-feeding along with the mother's clinical need for clonazepam and any potential adverse effects on the breast-fed infant from clonazepam or the underlying maternal condition.

    MECHANISM OF ACTION

    Benzodiazepines act at the level of the limbic, thalamic, and hypothalamic regions of the CNS, and can produce any level of CNS depression required including sedation, hypnosis, skeletal muscle relaxation, anticonvulsant activity, and coma. The action of these drugs is mediated through the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). Central benzodiazepine receptors interact allosterically with GABA receptors, potentiating the effects of GABA and thereby increasing the inhibition of the ascending reticular activating system. Benzodiazepines block the cortical and limbic arousal that occurs following stimulation of the reticular pathways.

    PHARMACOKINETICS

    Clonazepam is administered orally. It is distributed widely throughout body tissues and is approximately 85% bound to plasma proteins. The onset of action of clonazepam is 20 to 60 minutes and persists for up to 6 to 8 hours in children and up to 12 hours in adults. Clonazepam is extensively metabolized by the liver through CYP3A4 nitro-reduction to form the inactive metabolite 7-amino-clonazepam, which is further metabolized through N-acetyltransferase 2 (NAT-2) to 7-acetamido-clonazepam. During chronic therapy, the concentration of 7-amino-clonazepam can be as high or higher than the concentration of clonazepam. The enzyme NAT-2 is a polymorphic gene, generally dividing the population into slow and rapid acetylators. In one study, a significantly higher (about 2-fold) plasma concentration ratio of 7-amino-clonazepam to clonazepam was observed in patients with a normal CYP3A4 expression and a slower N-acetylation rate. Less than 2% of a dose is excreted in the urine as the parent compound; the 7-acetamido-clonazepam metabolite is excreted in the urine along with minor amounts of inactive 3-hydroxy metabolites. The half-life of clonazepam is approximately 22 to 33 hours in children and 19 to 50 hours in adults.
     
    Affected cytochrome P450 isoenzymes and drug transporters: CYP3A4
    Clonazepam is a substrate for the CYP3A4 isoenzyme.

    Oral Route

    Clonazepam is absorbed rapidly following an oral dose. The absolute bioavailability of clonazepam is approximately 90%. Maximum plasma concentrations are reached within 1 to 4 hours following oral administration.