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    Opioid Agonists and Other Drug Combinations

    BOXED WARNING

    Asthma, chronic obstructive pulmonary disease (COPD), coadministration with other CNS depressants, coma, cor pulmonale, hypoxemia, obesity, pulmonary disease, respiratory depression, respiratory insufficiency, scoliosis, sleep apnea, status asthmaticus

    Acetaminophen; hydrocodone is contraindicated for use in patients with significant respiratory depression and in patients with acute or severe asthma (e.g., status asthmaticus) in unmonitored care settings or in the absence of resuscitative equipment. Receipt of moderate hydrocodone doses in these patients may significantly decrease pulmonary ventilation. Additionally, avoid coadministration with other CNS depressants when possible, as this significantly increases the risk for profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for use in 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. Monitor patients closely for signs or symptoms of respiratory depression or sedation. In patients with chronic obstructive pulmonary disease (COPD), cor pulmonale, decreased respiratory reserve, hypoxia, hypercapnia, respiratory insufficiency, upper airway obstruction, or preexisting respiratory depression, it is recommended that non-opioid analgesics be considered as alternatives to hydrocodone, as even usual therapeutic doses of hydrocodone may decrease respiratory drive and cause apnea in these patient populations. Extreme caution should also be used in patients with chronic asthma, kyphoscoliosis (a type of scoliosis), hypoxemia, or paralysis of the phrenic nerve. Patients with advanced age, debilitation, or sleep apnea are at an increased risk for the development of respiratory depression associated with hydrocodone. Use with caution in patients with obesity as this is a risk factor for obstructive sleep-apnea syndrome and/or decreased respiratory reserve. Hydrocodone should not be used during impaired consciousness or coma, as significant decreases in respiratory drive may lead to adverse intracranial effects from carbon dioxide retention. Respiratory depression, if left untreated, may cause respiratory arrest and death. Symptoms of respiratory depression include a reduced urge to breathe, a decreased respiratory rate, or deep breaths separated by long pauses (a "sighing" breathing pattern). Carbon dioxide retention from respiratory depression may also worsen opioid sedating effects. Careful monitoring and dose titration is required, particularly when CYP450 3A4 inhibitors or inducers are used concomitantly; concurrent use of a CYP3A4 inhibitor or discontinuation of a concurrently used CYP3A4 inducer may increase plasma hydrocodone concentrations and potentiate the risk of fatal respiratory depression. Management of respiratory depression should include observation, necessary supportive measures, and opioid antagonist use when indicated.

    Alcoholism, ethanol ingestion, ethanol intoxication, hepatic disease, hepatitis, hepatotoxicity, malnutrition

    Acetaminophen has been associated with acute liver failure, with some cases resulting in liver transplant and death. Most cases of liver injury are associated with the use of acetaminophen at doses exceeding 4 g per day and often involve the use of more than 1 acetaminophen-containing product. Advise patients receiving acetaminophen to carefully read OTC and prescription labels, to avoid excessive and/or duplicate medications, and to seek medical help immediately if more than 4 g of acetaminophen is ingested in 1 day, even if they feel well. It is important to note that the risk of acetaminophen-induced hepatotoxicity is increased in patients with pre-existing hepatic disease (e.g., hepatitis), those who ingest alcohol (e.g., ethanol intoxication, alcoholism), those with chronic malnutrition, and those with severe dehydration. In patients with chronic hepatic disease, acetaminophen can be used safely in recommended doses and is often preferred to nonsteroidal anti-inflammatory drugs (NSAIDs) due to the absence of platelet impairment, gastrointestinal toxicity, and nephrotoxicity. Though the half-life of acetaminophen may be prolonged, repeated dosing does not result in drug or metabolite accumulation. In addition, cytochrome P450 activity is not increased and glutathione stores are not depleted in hepatically impaired patients taking therapeutic doses, therefore toxic metabolite formation and accumulation is not altered. Although it is always prudent to use the smallest dose of acetaminophen for the shortest duration necessary, courses less than 2 weeks in length have been administered safely to adult patients with stable chronic liver disease. If use acetaminophen in patients with severe hepatic disease, monitor serial liver function tests. Additionally, patients with hepatic impairment may have higher plasma hydrocodone concentrations compared to those with normal hepatic function. Use a low initial dose of acetaminophen; hydrocodone in patients with hepatic impairment, and monitor for sedation and respiratory depression. Consumption of ethanol will result in additive CNS depressant effects. Advise patients to avoid ethanol ingestion and ethanol intoxication, including the ingestion of alcohol contained in prescription or non-prescription medications, during therapy. Patients with alcoholism should be advised of this serious risk, or an alternative medication should be used.

    Depression, substance abuse

    Hydrocodone is an opioid agonist and therefore has abuse potential and risk of fatal overdose from depressed respiration. Addiction may occur in patients who obtain hydrocodone illicitly or in those appropriately prescribed the drug. The risk of addiction in any individual is unknown. However, patients with mental illness (e.g., major depression) or a family history of substance abuse (including alcoholism) have an increased risk of opioid abuse. Assess patients for risks of addiction, abuse, or misuse before drug initiation, and monitor patients who receive opioids routinely for development of these behaviors or conditions. A potential risk of abuse should not preclude appropriate pain management in any patient, but requires more intensive counseling and monitoring. Abuse and addiction are separate and distinct from physical dependence and tolerance; patients with addiction may not exhibit tolerance and symptoms of physical dependence. To discourage abuse, the smallest appropriate quantity of hydrocodone should be dispensed, and proper disposal instructions for unused drug should be given to patients.

    Accidental exposure, potential for overdose or poisoning

    Like all opioid analgesics, hydrocodone is associated with a significant potential for overdose or poisoning; proper patient selection and counseling is recommended. Hydrocodone should be kept out of the reach of pediatric patients, others for whom the drug was not prescribed, and pets as accidental exposure may cause respiratory failure and a fatal overdose.

    Labor, neonatal opioid withdrawal syndrome, obstetric delivery, pregnancy

    There are no adequate and well-controlled studies of acetaminophen; hydrocodone in pregnant women. Hydrocodone readily crosses the placenta. Use acetaminophen; hydrocodone during pregnancy only if the potential benefit clearly justifies the potential risk to the fetus. Hydrocodone is not recommended for use in women during and immediately prior to labor and obstetric delivery because oral opioid agonists may cause respiratory depression in the newborn. Opioid analgesics can prolong labor by reducing the strength and frequency of uterine contractions; however, this effect may be offset by an increased rate of cervical dilation. Further, prolonged maternal use of acetaminophen; hydrocodone during pregnancy may result in neonatal opioid withdrawal syndrome (NOWS). This syndrome can be life-threatening. Severe symptoms may require pharmacologic therapy managed by clinicians familiar with neonatal opioid withdrawal. Monitor the neonate for withdrawal symptoms including irritability, hyperactivity, abnormal sleep pattern, high-pitched crying, tremor, vomiting, diarrhea, and failure to gain weight. Onset, duration, and severity of opioid withdrawal may vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination by the newborn. No overall increase in fetal mortality, as determined by pregnancy outcomes of mothers that overdosed on various amounts of acetaminophen, was apparent in an analysis of 300 women. Treatment with acetylcysteine or methionine did not appear to affect fetal or neonatal toxicity. Of 235 babies exposed to an overdose of only acetaminophen, 168 were normal, 8 had malformations, 16 were spontaneously aborted, and 43 were electively terminated. Of 67 babies exposed to an overdose of a combination acetaminophen product, 51 were normal, 3 had malformations, 2 were spontaneously aborted (late fetal deaths), and 11 were electively terminated. None of the babies with malformations were exposed during the first trimester, but all of the spontaneous abortions and 1 of the late fetal deaths were subsequent to first trimester exposure.

    DEA CLASS

    Rx, schedule II

    DESCRIPTION

    Combination product to treat moderate to severe pain. Acetaminophen is a non-salicylate analgesic; hydrocodone is a semisynthetic opiate agonist. The combination produces additive analgesia as compared to either agent alone.

    COMMON BRAND NAMES

    Anexsia, Hycet, Lorcet, Lorcet HD, Lorcet Plus, Lortab, Norco, Verdrocet, Vicodin, Vicodin ES, Vicodin HP, Xodol, Zamicet

    HOW SUPPLIED

    Anexsia/Hydrocodone Bitartrate, Acetaminophen/Lorcet/Lorcet HD/Lorcet Plus/Lortab/Norco/Verdrocet/Vicodin/Vicodin ES/Vicodin HP/Xodol Oral Tab: 10-300mg, 10-325mg, 2.5-325mg, 5-300mg, 5-325mg, 7.5-300mg, 7.5-325mg
    Hycet/Hydrocodone Bitartrate, Acetaminophen/Lortab/Zamicet Oral Sol: 7.5mL, 15mL, 10-300mg, 10-325mg, 5-163mg, 7.5-325mg
    Hydrocodone Bitartrate, Acetaminophen Oral Elixir: 5mL, 2.5-167mg

    DOSAGE & INDICATIONS

    For the treatment of moderate pain to moderately severe pain.
    NOTE: FDA-approved dosages vary depending on product. Do not exceed a total daily dose of 4 grams of acetaminophen from ALL sources.
    Oral dosage (tablets containing 2.5 mg of hydrocodone and 325 mg of acetaminophen)
    Adults

    1 to 2 tablets every 4 to 6 hours as needed, not to exceed 12 tablets/day.

    Oral dosage (tablets or capsules containing 5 mg of hydrocodone and 300 to 500 mg of acetaminophen)
    Adults

    1 to 2 tablets or capsules every 4 to 6 hours as needed, not to exceed 8 tablets/day.

    Oral dosage (tablets containing 7.5 to 10 mg of hydrocodone and 300 to 660 mg of acetaminophen)
    Adults

    1 tablet every 4 to 6 hours as needed, not to exceed 6 tablets/day.

    Oral dosage (tablets containing 7.5 to 10 mg of hydrocodone and 750 mg of acetaminophen)
    Adults

    1 tablet every 4 to 6 hours as needed, not to exceed 5 tablets/day.

    Oral dosage (liquid containing hydrocodone/acetaminophen 7.5 mg/325 mg per 15 mL OR hydrocodone/acetaminophen 7.5 mg/500 mg per 15 mL)
    Adults and Adolescents 14 years and older weighing 46 kg or more

    15 mL PO every 4 to 6 hours as needed. Do not exceed 90 mL per day.

    Children and Adolescents 2 years and older weighing 32 to 45 kg

    10 mL PO every 4 to 6 hours as needed. Do not exceed 60 mL per day.

    Children 2 years and older weighing 23 to 31 kg

    7.5 mL PO every 4 to 6 hours as needed. Do not exceed 45 mL per day.

    Children 2 years and older weighing 16 to 22 kg

    5 mL PO every 4 to 6 hours as needed. Do not exceed 30 mL per day.

    Children 2 years and older weighing 12 to 15 kg

    3.75 mL PO every 4 to 6 hours as needed. Do not exceed 22.5 mL per day.

    Oral dosage (liquid containing hydrocodone/acetaminophen 10 mg/300 mg per 15 mL)
    Adults and Adolescents 14 years and older weighing 46 kg or more

    11.25 mL PO every 4 to 6 hours as needed. Do not exceed 67.5 mL per day.

    Children and Adolescents 2 years and older weighing 32 to 45 kg

    7.5 mL PO every 4 to 6 hours as needed. Do not exceed 45 mL per day.

    Children 2 years and older weighing 23 to 31 kg

    5.6 mL PO every 4 to 6 hours as needed. Do not exceed 33.6 mL per day.

    Children 2 years and older weighing 16 to 22 kg

    3.75 mL PO every 4 to 6 hours as needed. Do not exceed 22.5 mL per day.

    Children 2 years and older weighing 12 to 15 kg

    2.8 mL PO every 4 to 6 hours as needed. Do not exceed 16.8 mL per day.

    Oral dosage (liquid containing hydrocodone/acetaminophen 10 mg/325 mg per 15 mL)
    Adults

    15 mL PO every 4 to 6 hours as needed. Do not exceed 90 mL per day.

    Adolescents 14 years and older weighing 46 kg or more

    11.25 mL PO every 4 to 6 hours as needed. Do not exceed 67.5 mL per day.

    Children and Adolescents 2 years and older weighing 32 to 45 kg

    7.5 mL PO every 4 to 6 hours as needed. Do not exceed 45 mL per day.

    Children 2 years and older weighing 23 to 31 kg

    5.6 mL PO every 4 to 6 hours as needed. Do not exceed 33.6 mL per day.

    Children 2 years and older weighing 16 to 22 kg

    3.75 mL PO every 4 to 6 hours as needed. Do not exceed 22.5 mL per day.

    Children 2 years and older weighing 12 to 15 kg

    2.8 mL PO every 4 to 6 hours as needed. Do not exceed 16.8 mL per day.

    MAXIMUM DOSAGE

    Adults

    The maximum dosage is dependent on the product. Do not exceed a total daily dose of 4 grams of acetaminophen from ALL sources.

    Geriatric

    The maximum dosage is dependent on the product. Do not exceed a total daily dose of 4 grams of acetaminophen from ALL sources.

    Adolescents

    >= 46 kg (101 pounds): acetaminophen 3 g/day PO; the maximum dose of the hydrocodone in the combination product is limited by the total daily limit of acetaminophen.
    32—45 kg (70—100 pounds): acetaminophen 2 g/day PO; the maximum dose of the hydrocodone in the combination product is limited by the total daily limit of acetaminophen.

    Children

    >= 2 years and 23—31 kg (51—69 pounds): acetaminophen 1.5 g/day PO; the maximum dose of the hydrocodone in the combination product is limited by the total daily limit of acetaminophen.
    >= 2 years and 16—22 kg (35—50 pounds): acetaminophen 1 g/day PO; the maximum dose of the hydrocodone in the combination product is limited by the total daily limit of acetaminophen.
    >= 2 years and 12—15 kg (27—34 pounds): acetaminophen 750 mg/day PO; the maximum dose of the hydrocodone in the combination product is limited by the total daily limit of acetaminophen.
    < 2 years or < 12 kg: Safety and efficacy have not been established.

    Infants

    Safety and efficacy have not been established.

    Neonates

    Safety and efficacy have not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Dosage should be modified depending upon the clinical response and degree of hepatic impairment. No quantitative recommendations are available.

    Renal Impairment

    Dosage should be modified depending upon the clinical response and degree of renal impairment. No quantitative recommendations are available.

    ADMINISTRATION

    Oral Administration

    Administer with a full glass of water. May be taken food or milk to minimize GI irritation.
    Acetaminophen; hydrocodone should be titrated to the dose required to relieve the patient's pain keeping in mind the maximum daily dose of acetaminophen. Careful titration in opioid-naive patients is required until tolerance develops to some of the side effects (i.e., drowsiness, respiratory depression).

    STORAGE

    Generic:
    - Avoid exposure to heat
    - Do not refrigerate
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Anexsia:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Bancap HC :
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Ceta-Plus:
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Co-Gesic:
    - Protect from light
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Comfortpak :
    - Protect from light
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Dolagesic:
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Dolorex Forte:
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)
    DuoCet :
    - Protect from light
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Hycet:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Hydrocet :
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Hydrogesic:
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Liquicet:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Lorcet:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Lorcet HD:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Lorcet Plus:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Lortab:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Margesic H:
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Maxidone:
    - Store between 68 to 77 degrees F
    Norco:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Polygesic:
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Stagesic:
    - Protect from light
    - Protect from moisture
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Vanacet:
    - Protect from light
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Verdrocet:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Vicodin:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Vicodin ES:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Vicodin HP:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Xodol:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Zamicet :
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Zolvit :
    - Do not refrigerate
    - Protect from extreme heat
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Zydone:
    - Store at 77 degrees F; excursions permitted to 59-86 degrees F

    CONTRAINDICATIONS / PRECAUTIONS

    General Information

    NOTE: This monograph discusses the contraindications/precautions of acetaminophen; hydrocodone combination products. Clinicians may wish to consult the individual monographs for more information about each agent.

    Acetaminophen hypersensitivity, opiate agonist hypersensitivity

    Acetaminophen; hydrocodone is contraindicated in patients with acetaminophen hypersensitivity. Acetaminophen hypersensitivity reactions are rare, but severe sensitivity reactions are possible. Although true opiate agonist hypersensitivity is rare, the use of acetaminophen; hydrocodone is contraindicated in patients with hydrocodone hypersensitivity.

    Acute abdomen, biliary tract disease, constipation, GI disease, GI obstruction, ileus, inflammatory bowel disease, pancreatitis, ulcerative colitis

    Hydrocodone is contraindicated in patients with known or suspected GI obstruction, including paralytic ileus. Due to the effects of opioid agonists on the gastrointestinal tract, hydrocodone should be used cautiously in patients with GI disease, such as ulcerative colitis (UC). Patients with UC or other inflammatory bowel disease may be more sensitive to constipation caused by opioid agonists. Post-operative patients should be monitored for decreased bowel motility. Opioid agonists may obscure the diagnosis or clinical course in patients with acute abdomen. As with other opioid agonists, hydrocodone may cause spasm of the sphincter of Oddi. Hydrocodone should be used with caution in patients with biliary tract disease, including acute pancreatitis.

    Asthma, chronic obstructive pulmonary disease (COPD), coadministration with other CNS depressants, coma, cor pulmonale, hypoxemia, obesity, pulmonary disease, respiratory depression, respiratory insufficiency, scoliosis, sleep apnea, status asthmaticus

    Acetaminophen; hydrocodone is contraindicated for use in patients with significant respiratory depression and in patients with acute or severe asthma (e.g., status asthmaticus) in unmonitored care settings or in the absence of resuscitative equipment. Receipt of moderate hydrocodone doses in these patients may significantly decrease pulmonary ventilation. Additionally, avoid coadministration with other CNS depressants when possible, as this significantly increases the risk for profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for use in 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. Monitor patients closely for signs or symptoms of respiratory depression or sedation. In patients with chronic obstructive pulmonary disease (COPD), cor pulmonale, decreased respiratory reserve, hypoxia, hypercapnia, respiratory insufficiency, upper airway obstruction, or preexisting respiratory depression, it is recommended that non-opioid analgesics be considered as alternatives to hydrocodone, as even usual therapeutic doses of hydrocodone may decrease respiratory drive and cause apnea in these patient populations. Extreme caution should also be used in patients with chronic asthma, kyphoscoliosis (a type of scoliosis), hypoxemia, or paralysis of the phrenic nerve. Patients with advanced age, debilitation, or sleep apnea are at an increased risk for the development of respiratory depression associated with hydrocodone. Use with caution in patients with obesity as this is a risk factor for obstructive sleep-apnea syndrome and/or decreased respiratory reserve. Hydrocodone should not be used during impaired consciousness or coma, as significant decreases in respiratory drive may lead to adverse intracranial effects from carbon dioxide retention. Respiratory depression, if left untreated, may cause respiratory arrest and death. Symptoms of respiratory depression include a reduced urge to breathe, a decreased respiratory rate, or deep breaths separated by long pauses (a "sighing" breathing pattern). Carbon dioxide retention from respiratory depression may also worsen opioid sedating effects. Careful monitoring and dose titration is required, particularly when CYP450 3A4 inhibitors or inducers are used concomitantly; concurrent use of a CYP3A4 inhibitor or discontinuation of a concurrently used CYP3A4 inducer may increase plasma hydrocodone concentrations and potentiate the risk of fatal respiratory depression. Management of respiratory depression should include observation, necessary supportive measures, and opioid antagonist use when indicated.

    Abrupt discontinuation

    Abrupt discontinuation of prolonged hydrocodone therapy can result in opioid withdrawal symptoms. In patients who have received acetaminophen; hydrocodone around the clock for 5 days or more, gradually reduce the dose by 25% to 50% every 2 to 4 days while monitoring for signs and symptoms of withdrawal. Avoid use of partial agonists (e.g., buprenorphine), mixed agonist/antagonists (e.g., nalbuphine), or pure antagonists (e.g., naloxone) in patients physically dependent on opioids, as an acute withdrawal syndrome may precipitate. The severity of the withdrawal syndrome produced will depend on the degree of physical dependence and on the administered dose of the concomitant drug. If treatment of respiratory depression in an individual physically dependent on opioids is necessary, administer the opioid antagonist with extreme care; titrate the antagonist dose by using smaller than usual doses. In addition, the use of partial agonists or mixed agonist/antagonists in patients who have received or are receiving hydrocodone should be avoided as these medications may reduce the analgesic effect of hydrocodone.

    Alcoholism, ethanol ingestion, ethanol intoxication, hepatic disease, hepatitis, hepatotoxicity, malnutrition

    Acetaminophen has been associated with acute liver failure, with some cases resulting in liver transplant and death. Most cases of liver injury are associated with the use of acetaminophen at doses exceeding 4 g per day and often involve the use of more than 1 acetaminophen-containing product. Advise patients receiving acetaminophen to carefully read OTC and prescription labels, to avoid excessive and/or duplicate medications, and to seek medical help immediately if more than 4 g of acetaminophen is ingested in 1 day, even if they feel well. It is important to note that the risk of acetaminophen-induced hepatotoxicity is increased in patients with pre-existing hepatic disease (e.g., hepatitis), those who ingest alcohol (e.g., ethanol intoxication, alcoholism), those with chronic malnutrition, and those with severe dehydration. In patients with chronic hepatic disease, acetaminophen can be used safely in recommended doses and is often preferred to nonsteroidal anti-inflammatory drugs (NSAIDs) due to the absence of platelet impairment, gastrointestinal toxicity, and nephrotoxicity. Though the half-life of acetaminophen may be prolonged, repeated dosing does not result in drug or metabolite accumulation. In addition, cytochrome P450 activity is not increased and glutathione stores are not depleted in hepatically impaired patients taking therapeutic doses, therefore toxic metabolite formation and accumulation is not altered. Although it is always prudent to use the smallest dose of acetaminophen for the shortest duration necessary, courses less than 2 weeks in length have been administered safely to adult patients with stable chronic liver disease. If use acetaminophen in patients with severe hepatic disease, monitor serial liver function tests. Additionally, patients with hepatic impairment may have higher plasma hydrocodone concentrations compared to those with normal hepatic function. Use a low initial dose of acetaminophen; hydrocodone in patients with hepatic impairment, and monitor for sedation and respiratory depression. Consumption of ethanol will result in additive CNS depressant effects. Advise patients to avoid ethanol ingestion and ethanol intoxication, including the ingestion of alcohol contained in prescription or non-prescription medications, during therapy. Patients with alcoholism should be advised of this serious risk, or an alternative medication should be used.

    Depression, substance abuse

    Hydrocodone is an opioid agonist and therefore has abuse potential and risk of fatal overdose from depressed respiration. Addiction may occur in patients who obtain hydrocodone illicitly or in those appropriately prescribed the drug. The risk of addiction in any individual is unknown. However, patients with mental illness (e.g., major depression) or a family history of substance abuse (including alcoholism) have an increased risk of opioid abuse. Assess patients for risks of addiction, abuse, or misuse before drug initiation, and monitor patients who receive opioids routinely for development of these behaviors or conditions. A potential risk of abuse should not preclude appropriate pain management in any patient, but requires more intensive counseling and monitoring. Abuse and addiction are separate and distinct from physical dependence and tolerance; patients with addiction may not exhibit tolerance and symptoms of physical dependence. To discourage abuse, the smallest appropriate quantity of hydrocodone should be dispensed, and proper disposal instructions for unused drug should be given to patients.

    CNS depression, head trauma, increased intracranial pressure, intracranial mass, psychosis

    Use hydrocodone with caution in patients with CNS depression, toxic psychosis, head trauma, intracranial mass, or increased intracranial pressure. Monitor for signs of drowsiness and depressed respirations, particularly when initiating hydrocodone. Opioids may aggravate such conditions and alter neurologic parameters (e.g., level of consciousness, pupillary responses). Hydrocodone-induced hypoventilation can produce cerebral hypoxia, carbon dioxide retention, and raise CSF pressure. Avoid the use of hydrocodone in patients with impaired consciousness.

    Angina, cardiac arrhythmias, cardiac disease, dehydration, hypotension, hypovolemia, orthostatic hypotension, shock

    Opioid agonists, such as hydrocodone, produce cholinergic side effects (by stimulating medullary vagal nuclei) causing bradycardia and vasovagal syncope, and induce the release of histamine. In patients who are unable to maintain blood pressure due to hypovolemia or dehydration, or in those who concurrently receive other agents that compromise vasomotor tone (e.g., phenothiazines or general anesthetics), opioid agonists may induce peripheral vasodilatation and severe hypotension. These effects can cause problems in patients with cardiac disease (e.g., angina, heart failure). Hydrocodone should be used with caution in patients with cardiac arrhythmias or orthostatic hypotension and should not be used in patients with circulatory shock. Monitor patients for hypotension following hydrocodone initiation and dose titrations.

    Bladder obstruction, oliguria, prostatic hypertrophy, renal impairment, urethral stricture, urinary retention

    Acetaminophen; hydrocodone should be used cautiously in patients with renal impairment or renal failure; dosage adjustments may be required. Hydrocodone can cause urinary retention and oliguria, due to increasing the tension of the detrusor muscle. Patients more prone to these effects include those with prostatic hypertrophy, urethral stricture, bladder obstruction, or pelvic tumors. In addition, hydrocodone may accumulate in these patients leading to a prolonged duration of action and potential increase in side effects. Chronic acetaminophen administration should be avoided in patients with underlying renal disease; however it may be used for episodic pain.

    Geriatric

    Use hydrocodone with caution in geriatric or debilitated patients. Geriatric or debilitated patients are more susceptible to adverse reactions, especially sedation and respiratory depression, probably as a result of altered distribution of the drug or decreased elimination. Initial doses may need to be reduced, and doses should be carefully titrated taking into account analgesic effects, adverse reactions, and concomitant drugs that may depress respiration. According to the Beers Criteria, opiate agonists are considered potentially inappropriate medications (PIMs) in geriatric patients with a history of falls or fractures and should be avoided in these patient populations, with the exception of pain management due to recent fractures or joint replacement, since opiates can produce ataxia, impaired psychomotor function, syncope, and additional falls. If an opiate must be used, consider reducing use of other CNS-active medications that increase the risk of falls and fractures and implement other strategies to reduce fall risk. Individuals receiving palliative care or those in hospice settings are excluded from the Beers Criteria; the balance of benefits and harms of medication management for these patients may differ from those of the general population of older adults. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities (LTCFs). The Guidelines caution that opioids may cause constipation, nausea, vomiting, sedation, lethargy, weakness, confusion, dysphoria, physical and psychological dependency, hallucinations, and unintended respiratory depression, especially in individuals with compromised pulmonary function. These adverse effects can lead to other consequences such as falls. In addition, the initiation of longer-acting opioids is not recommended unless shorter-acting opioids have been unsuccessful, or titration of shorter-acting doses has established a clear daily dose of opioid analgesic that can be provided by using a long-acting form.

    Children, infants, neonates

    Opioid agonists, including acetaminophen; hydrocodone products, are used in children for moderate to severe pain. Acetaminophen; hydrocodone is not indicated for neonates, infants, or children < 2 years of age; and, the safety and efficacy of the tablet and capsule formulations have not been established in pediatric patients. Children weighing < 50 kg may be more sensitive to the effects of opioid agonists and require body weight dosing of opioid agonists.

    G6PD deficiency

    Patients with G6PD deficiency who overdose with acetaminophen may be at increased risk for drug-induced hemolysis. Practitioners should be aware of this potential complication and monitor at-risk patients for signs and symptoms of hemolysis. Conflicting data exists on whether therapeutic doses of acetaminophen can cause hemolysis in G6PD deficient patients. However, a direct cause and effect relationship has not been well established and therefore, therapeutic doses are generally considered safe in this population.

    Bone marrow suppression, immunosuppression, infection, neutropenia

    Symptoms of acute infection (e.g., fever, pain) can be masked during treatment with acetaminophen in patients with bone marrow suppression, especially neutropenia, or immunosuppression.

    Driving or operating machinery

    Any patient receiving acetaminophen; hydrocodone should be warned about the possibility of sedation and to use caution when driving or operating machinery.

    Adrenal insufficiency, hypothyroidism, myxedema

    Use hydrocodone with caution in patients with adrenal insufficiency (i.e., Addison's disease), hypothyroidism, or myxedema. Such patients may be at increased risk of adverse events. Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and luteinizing hormone (LH); however, the thyroid stimulating hormone may be either stimulated or inhibited by opioids. Rarely, adrenal insufficiency has been reported in association with opioid use. Patients should seek immediate medical attention if they experience symptoms such as nausea, vomiting, loss of appetite, fatigue, weakness, dizziness, or hypotension. If adrenocortical insufficiency is suspected, confirm with diagnostic testing as soon as possible. If diagnosed, the patient should be treated with physiologic replacement doses of corticosteroids, and if appropriate, weaned off of opioid therapy. If the opioid can be discontinued, a follow-up assessment of adrenal function should be performed to determine if corticosteroid treatment can be discontinued. Other opioids may be tried; some cases reported use of a different opioid with no recurrence of adrenocortical insufficiency. It is unclear which, if any, opioids are more likely to cause adrenocortical insufficiency. In addition, chronic opioid use may lead to symptoms of hypogonadism, resulting from changes in the hypothalamic-pituitary-gonadal axis. Monitor patients for symptoms of opioid-induced endocrinopathy, particularly those receiving a daily dose equivalent to 100 mg or more of morphine. Patients presenting with signs or symptoms of androgen deficiency should undergo laboratory evaluation.

    Accidental exposure, potential for overdose or poisoning

    Like all opioid analgesics, hydrocodone is associated with a significant potential for overdose or poisoning; proper patient selection and counseling is recommended. Hydrocodone should be kept out of the reach of pediatric patients, others for whom the drug was not prescribed, and pets as accidental exposure may cause respiratory failure and a fatal overdose.

    Seizure disorder, seizures

    Seizures can be precipitated by opioid agonists in patients with a preexisting seizure disorder. The incidence of these effects during hydrocodone therapy is not known, but appears to be rare at normal doses. Monitor patients with a history of seizure disorders for worsened seizure control during therapy.

    Labor, neonatal opioid withdrawal syndrome, obstetric delivery, pregnancy

    There are no adequate and well-controlled studies of acetaminophen; hydrocodone in pregnant women. Hydrocodone readily crosses the placenta. Use acetaminophen; hydrocodone during pregnancy only if the potential benefit clearly justifies the potential risk to the fetus. Hydrocodone is not recommended for use in women during and immediately prior to labor and obstetric delivery because oral opioid agonists may cause respiratory depression in the newborn. Opioid analgesics can prolong labor by reducing the strength and frequency of uterine contractions; however, this effect may be offset by an increased rate of cervical dilation. Further, prolonged maternal use of acetaminophen; hydrocodone during pregnancy may result in neonatal opioid withdrawal syndrome (NOWS). This syndrome can be life-threatening. Severe symptoms may require pharmacologic therapy managed by clinicians familiar with neonatal opioid withdrawal. Monitor the neonate for withdrawal symptoms including irritability, hyperactivity, abnormal sleep pattern, high-pitched crying, tremor, vomiting, diarrhea, and failure to gain weight. Onset, duration, and severity of opioid withdrawal may vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination by the newborn. No overall increase in fetal mortality, as determined by pregnancy outcomes of mothers that overdosed on various amounts of acetaminophen, was apparent in an analysis of 300 women. Treatment with acetylcysteine or methionine did not appear to affect fetal or neonatal toxicity. Of 235 babies exposed to an overdose of only acetaminophen, 168 were normal, 8 had malformations, 16 were spontaneously aborted, and 43 were electively terminated. Of 67 babies exposed to an overdose of a combination acetaminophen product, 51 were normal, 3 had malformations, 2 were spontaneously aborted (late fetal deaths), and 11 were electively terminated. None of the babies with malformations were exposed during the first trimester, but all of the spontaneous abortions and 1 of the late fetal deaths were subsequent to first trimester exposure.

    Breast-feeding

    Consider the developmental and health benefits of breast-feeding along with the mother's clinical need for acetaminophen; hydrocodone and any potential adverse effects on the breast-fed infant from the drugs or the underlying maternal condition. Hydrocodone is distributed into breast milk at varying degrees depending upon the dose. Acetaminophen also crosses into breast milk with a concentration ranging from 0.1% to 1.85% of the maternal dose. A pharmacokinetic study in 30 women receiving acetaminophen; hydrocodone for postpartum pain found that breast fed newborns (postnatal age 3 to 11 days) received a median of 1.6% (range 0.2% to 9%) of the maternal weight-adjusted hydrocodone dosage. The total opiate dosage via breast milk, including the active metabolite hydromorphone, was found to be 0.7% of a therapeutic dosage used for older infants. The authors concluded that doses of hydrocodone given to breast-feeding mothers should be limited to 30 mg/day and doses higher than 40 mg/day should be avoided. As with all opioid-containing products, if acetaminophen; hydrocodone is used by a breast-feeding mother, the infant should be monitored for sedation and respiratory depression. Withdrawal symptoms can occur in breast-fed infants when maternal administration of an opioid analgesic is stopped, or when breast-feeding is stopped. Previous American Academy of Pediatrics (AAP) recommendations considered acetaminophen as usually compatible with breast-feeding. Other alternative analgesics considered to be usually compatible with breast-feeding by the AAP include ibuprofen and morphine; the use of hydrocodone in breast-feeding women was not evaluated by the AAP.

    Infertility, reproductive risk

    Chronic opioid use may influence the hypothalamic-pituitary-gonadal axis, leading to hormonal changes that may manifest as hypogonadism (gonadal suppression) and pose a reproductive risk. Although the exact causal role of opioids in the clinical manifestations of hypogonadism is unknown, patients could experience libido decrease, impotence, amenorrhea, or infertility. It is not known whether the effects on fertility are reversible. Monitor patients for symptoms of opioid-induced endocrinopathy. Patients presenting with signs or symptoms of androgen deficiency should undergo laboratory evaluation.

    ADVERSE REACTIONS

    Severe

    acute generalized exanthematous pustulosis (AGEP) / Delayed / 0-1.0
    toxic epidermal necrolysis / Delayed / 0-1.0
    Stevens-Johnson syndrome / Delayed / 0-1.0
    neonatal opioid withdrawal syndrome / Delayed / Incidence not known
    apnea / Delayed / Incidence not known
    GI bleeding / Delayed / Incidence not known
    peptic ulcer / Delayed / Incidence not known
    hepatotoxicity / Delayed / Incidence not known
    hepatic necrosis / Delayed / Incidence not known
    renal failure (unspecified) / Delayed / Incidence not known
    renal papillary necrosis / Delayed / Incidence not known
    interstitial nephritis / Delayed / Incidence not known
    renal tubular necrosis / Delayed / Incidence not known
    methemoglobinemia / Early / Incidence not known
    agranulocytosis / Delayed / Incidence not known
    pancytopenia / Delayed / Incidence not known
    hemolytic anemia / Delayed / Incidence not known
    anaphylactoid reactions / Rapid / Incidence not known
    anaphylactic shock / Rapid / Incidence not known
    angioedema / Rapid / Incidence not known
    exfoliative dermatitis / Delayed / Incidence not known
    cardiac arrest / Early / Incidence not known
    bradycardia / Rapid / Incidence not known
    hearing loss / Delayed / Incidence not known
    SIADH / Delayed / Incidence not known
    serotonin syndrome / Delayed / Incidence not known

    Moderate

    constipation / Delayed / 15.0-90.0
    withdrawal / Early / 1.0
    physiological dependence / Delayed / 10.0
    psychological dependence / Delayed / 10.0
    euphoria / Early / 10.0
    tolerance / Delayed / Incidence not known
    dyspnea / Early / Incidence not known
    respiratory depression / Rapid / Incidence not known
    hepatitis / Delayed / Incidence not known
    encephalopathy / Delayed / Incidence not known
    hypoprothrombinemia / Delayed / Incidence not known
    elevated hepatic enzymes / Delayed / Incidence not known
    bleeding / Early / Incidence not known
    jaundice / Delayed / Incidence not known
    urinary retention / Early / Incidence not known
    hallucinations / Early / Incidence not known
    hypotonia / Delayed / Incidence not known
    impaired cognition / Early / Incidence not known
    dysphoria / Early / Incidence not known
    confusion / Early / Incidence not known
    hemolysis / Early / Incidence not known
    thrombocytopenia / Delayed / Incidence not known
    anemia / Delayed / Incidence not known
    thrombocytosis / Delayed / Incidence not known
    prolonged bleeding time / Delayed / Incidence not known
    neutropenia / Delayed / Incidence not known
    edema / Delayed / Incidence not known
    erythema / Early / Incidence not known
    contact dermatitis / Delayed / Incidence not known
    orthostatic hypotension / Delayed / Incidence not known
    hypotension / Rapid / Incidence not known
    palpitations / Early / Incidence not known
    hypoglycemia / Early / Incidence not known
    hyponatremia / Delayed / Incidence not known
    impotence (erectile dysfunction) / Delayed / Incidence not known
    infertility / Delayed / Incidence not known
    adrenocortical insufficiency / Delayed / Incidence not known

    Mild

    nausea / Early / 27.0-27.0
    vomiting / Early / 9.0-16.0
    dizziness / Early / 5.0-16.0
    drowsiness / Early / 9.3-15.0
    headache / Early / 12.0-12.0
    xerostomia / Early / 3.0-3.0
    pruritus / Rapid / 3.0-3.0
    dyspepsia / Early / 1.0-1.0
    miosis / Early / 10.0
    pyrosis (heartburn) / Early / Incidence not known
    anorexia / Delayed / Incidence not known
    abdominal pain / Early / Incidence not known
    psychomotor impairment / Early / Incidence not known
    restlessness / Early / Incidence not known
    anxiety / Delayed / Incidence not known
    lethargy / Early / Incidence not known
    malaise / Early / Incidence not known
    purpura / Delayed / Incidence not known
    urticaria / Rapid / Incidence not known
    fever / Early / Incidence not known
    maculopapular rash / Early / Incidence not known
    rash / Early / Incidence not known
    syncope / Early / Incidence not known
    diaphoresis / Early / Incidence not known
    amenorrhea / Delayed / Incidence not known
    libido decrease / Delayed / Incidence not known
    gonadal suppression / Delayed / Incidence not known

    DRUG INTERACTIONS

    Abacavir; Lamivudine, 3TC; Zidovudine, ZDV: (Minor) Both acetaminophen and zidovudine, ZDV undergo glucuronidation. Competition for the metabolic pathway is thought to have caused a case of acetaminophen-related hepatotoxicity. This interaction may be more clinically significant in patients with depleted glutathione stores, such as patients with acquired immunodeficiency syndrome, poor nutrition, or alcoholism.
    Abiraterone: (Moderate) Concomitant use of hydrocodone with abiraterone may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of abiraterone could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If abiraterone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Abiraterone is a moderate inhibitor of CYP2D6.
    Acarbose: (Minor) It has been suggested by in vitro and in vivo animal studies that acarbose augments the activity of the hepatic isoenzyme CYP2E1, which is responsible for metabolism of acetaminophen to its toxic reactive metabolite. Patients should avoid the combination of acarbose with acetaminophen and ethanol until more is known about the potential for clinically significant interactions.
    Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Acetaminophen; Butalbital: (Major) Concomitant use of hydrocodone with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when hydrocodone is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of hydrocodone with a barbiturate can decrease hydrocodone concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; hydrocodone is a CYP3A4 substrate. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
    Acetaminophen; Butalbital; Caffeine: (Major) Concomitant use of hydrocodone with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when hydrocodone is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of hydrocodone with a barbiturate can decrease hydrocodone concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; hydrocodone is a CYP3A4 substrate. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
    Acetaminophen; Butalbital; Caffeine; Codeine: (Major) Concomitant use of hydrocodone with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when hydrocodone is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of hydrocodone with a barbiturate can decrease hydrocodone concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; hydrocodone is a CYP3A4 substrate. (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
    Acetaminophen; Caffeine; Dihydrocodeine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
    Acetaminophen; Caffeine; Magnesium Salicylate; Phenyltoloxamine: (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. Although salicylates are rarely associated with nephrotoxicity, high-dose, chronic administration of salicylates combined other analgesics, including acetaminophen, significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Additive hepatic toxicity may occur, especially in combined overdose situations. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Acetaminophen; Chlorpheniramine; Phenylephrine; Phenyltoloxamine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Acetaminophen; Codeine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
    Acetaminophen; Dextromethorphan; Doxylamine: (Moderate) Concomitant use of opioid agonists with doxylamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with doxylamine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Acetaminophen; Dichloralphenazone; Isometheptene: (Moderate) Concomitant use of hydrocodone with other central nervous system depressants can potentiate the effects of hydrocodone and may lead to additive CNS or respiratory depression. If hydrocodone is used with a CNS depressant, the dose of one or both drugs should be reduced.
    Acetaminophen; Diphenhydramine: (Moderate) Concomitant use of opioid agonists with diphenhydramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with diphenhydramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Acetaminophen; Oxycodone: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. Monitor patients for sedation and respiratory depression.
    Acetaminophen; Pentazocine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as hydrocodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of hydrocodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
    Acetaminophen; Propoxyphene: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
    Acetaminophen; Tramadol: (Major) Concomitant use of tramadol increases the seizure risk in patients taking opiate agonists. Also, tramadol can cause additive CNS depression and respiratory depression when used with opiate agonists; avoid concurrent use whenever possible. If used together, extreme caution is needed, and a reduced tramadol dose is recommended.
    Acrivastine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with acrivastine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with acrivastine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    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 or psychotropic activity such as opiate agonists. In addition, aldesleukin, IL-2, is a CYP3A4 inhibitor and may increase oxycodone plasma concentrations and related toxicities including potentially fatal respiratory depression. If therapy with both agents is necessary, monitor patients for an extended period and adjust oxycodone dosage as necessary.
    Alfentanil: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
    Aliskiren; Amlodipine: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with amlodipine is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If amlodipine is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like amlodipine can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If amlodipine is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
    Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with amlodipine is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If amlodipine is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like amlodipine can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If amlodipine is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Almotriptan: (Major) Because of the potential risk and severity of serotonin syndrome, caution and careful monitoring are recommended when administering serotonin-receptor agonists with other drugs that have serotonergic properties such as opioids. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Hydrocodone and the serotonin-receptor agonist should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Alosetron: (Major) Patients taking medications that decrease GI motility may be at greater risk for serious complications from alosetron, like constipation, via a pharmacodynamic interaction. Constipation is the most frequently reported adverse effect with alosetron. Alosetron, if used with drugs such as opiate agonists, may seriously worsen constipation, leading to events such as GI obstruction/impaction or paralytic ileus.
    Alprazolam: (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.
    Aluminum Hydroxide; Magnesium Hydroxide: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as magnesium hydroxide, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Aluminum Hydroxide; Magnesium Hydroxide; Simethicone: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as magnesium hydroxide, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Alvimopan: (Moderate) Patients should not take alvimopan if they have received therapeutic doses of opiate agonists for more than seven consecutive days immediately before initiation of alvimopan therapy. Patients recently exposed to opioids are expected to be more sensitive to the effects of mu-opioid receptor antagonists and may experience adverse effects localized to the gastrointestinal tract such as abdominal pain, nausea, vomiting, and diarrhea.
    Amide local anesthetics: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics 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. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Amifampridine: (Moderate) Carefully consider the need for concomitant treatment with opioid agonists and amifampridine, as coadministration may increase the risk of seizures. If coadministration occurs, closely monitor patients for seizure activity. Seizures have been observed in patients without a history of seizures taking amifampridine at recommended doses. Opioid agonists may increase the risk of seizures.
    Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Amiodarone: (Moderate) Concomitant use of hydrocodone with amiodarone may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of amiodarone could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If amiodarone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Amiodarone is an inhibitor of CYP3A4 and CYP2D6.
    Amitriptyline; Chlordiazepoxide: (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.
    Amlodipine: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with amlodipine is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If amlodipine is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like amlodipine can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If amlodipine is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
    Amlodipine; Atorvastatin: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with amlodipine is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If amlodipine is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like amlodipine can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If amlodipine is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
    Amlodipine; Benazepril: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with amlodipine is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If amlodipine is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like amlodipine can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If amlodipine is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
    Amlodipine; Hydrochlorothiazide, HCTZ; Olmesartan: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with amlodipine is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If amlodipine is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like amlodipine can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If amlodipine is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Amlodipine; Hydrochlorothiazide, HCTZ; Valsartan: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with amlodipine is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If amlodipine is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like amlodipine can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If amlodipine is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Amlodipine; Olmesartan: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with amlodipine is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If amlodipine is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like amlodipine can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If amlodipine is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
    Amlodipine; Telmisartan: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with amlodipine is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If amlodipine is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like amlodipine can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If amlodipine is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
    Amlodipine; Valsartan: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with amlodipine is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If amlodipine is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like amlodipine can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If amlodipine is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
    Amobarbital: (Major) Concomitant use of hydrocodone with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when hydrocodone is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of hydrocodone with a barbiturate can decrease hydrocodone concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; hydrocodone is a CYP3A4 substrate. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
    Amoxapine: (Major) Concomitant use of opioid agonists with amoxapine may cause excessive sedation, somnolence, and increased risk of serotonin syndrome. Avoid prescribing opioid cough medications in patients taking amoxapine. Limit the use of opioid pain medications with amoxapine 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. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome.
    Amoxicillin; Clarithromycin; Lansoprazole: (Moderate) Concomitant use of hydrocodone with clarithromycin may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of clarithromycin could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If clarithromycin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Clarithromycin is a strong inhibitor of CYP3A4.
    Amoxicillin; Clarithromycin; Omeprazole: (Moderate) Concomitant use of hydrocodone with clarithromycin may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of clarithromycin could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If clarithromycin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Clarithromycin is a strong inhibitor of CYP3A4.
    Antacids: (Minor) Antacids can delay the oral absorption of acetaminophen, but the interactions are not likely to be clinically significant as the extent of acetaminophen absorption is not appreciably affected.
    Anticholinergics: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Apalutamide: (Moderate) Concomitant use of hydrocodone with apalutamide can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If apalutamide is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and apalutamide is a strong CYP3A4 inducer.
    Apomorphine: (Major) Concomitant use of opioid agonists with apomorphine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking apomorphine. Limit the use of opioid pain medications with entacapone 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. Educate patients about the risks and symptoms of excessive CNS depression. Dopaminergic agents like apomorphine have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment.
    Apraclonidine: (Minor) Theoretically, apraclonidine might potentiate the effects of CNS depressant drugs such as opiate agonists. Although no specific drug interactions were identified with systemic agents and apraclonidine during clinical trials, apraclonidine can cause dizziness and somnolence.
    Aprepitant, Fosaprepitant: (Moderate) Concomitant use of hydrocodone with oral, multi-day regimens of aprepitant may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of aprepitant could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If aprepitant is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Aprepitant, when administered as a 3-day oral regimen (125 mg/80 mg/80 mg), is a moderate CYP3A4 inhibitor. (Minor) Use caution if acetaminophen and aprepitant are used concurrently and monitor for an increase in acetaminophen-related adverse effects for several days after administration of a multi-day aprepitant regimen. Acetaminophen is a minor (10 to 15%) substrate of CYP3A4. 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 acetaminophen. 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.
    Armodafinil: (Moderate) Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal if coadministration with armodafinil is necessary; consider increasing the dose of hydrocodone as needed. If armodafinil is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and armodafinil is a weak CYP3A4 inducer. Concomitant use with CYP3A4 inducers can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
    Artemether; Lumefantrine: (Moderate) Concomitant use of hydrocodone with artemether; lumefantrine may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of artemether; lumefantrine could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If artemether; lumefantrine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Artemether; lumefantrine is a moderate inhibitor of CYP2D6.
    Articaine; Epinephrine: (Moderate) Coadministration of articaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue articaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics 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. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Asenapine: (Moderate) Concomitant use of opioid agonists with asenapine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking asenapine. Limit the use of opioid pain medications with asenapine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Aspirin, ASA: (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Aspirin, ASA; Butalbital; Caffeine: (Major) Concomitant use of hydrocodone with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when hydrocodone is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of hydrocodone with a barbiturate can decrease hydrocodone concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; hydrocodone is a CYP3A4 substrate. (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
    Aspirin, ASA; Butalbital; Caffeine; Codeine: (Major) Concomitant use of hydrocodone with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when hydrocodone is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of hydrocodone with a barbiturate can decrease hydrocodone concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; hydrocodone is a CYP3A4 substrate. (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
    Aspirin, ASA; Caffeine; Dihydrocodeine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Aspirin, ASA; Carisoprodol: (Major) Concomitant use of hydrocodone with a skeletal muscle relaxant may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients taking a skeletal muscle relaxant. Limit the use of opioid pain medications with a skeletal muscle relaxant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Aspirin, ASA; Carisoprodol; Codeine: (Major) Concomitant use of hydrocodone with a skeletal muscle relaxant may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients taking a skeletal muscle relaxant. Limit the use of opioid pain medications with a skeletal muscle relaxant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Aspirin, ASA; Dipyridamole: (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Aspirin, ASA; Omeprazole: (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Aspirin, ASA; Oxycodone: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. Monitor patients for sedation and respiratory depression. (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Aspirin, ASA; Pravastatin: (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. High-dose, chronic administration of the combined analgesics significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Atazanavir: (Moderate) Concomitant use of hydrocodone with atazanavir may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of atazanavir could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If atazanavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Atazanavir is a strong inhibitor of CYP3A4.
    Atazanavir; Cobicistat: (Moderate) Concomitant use of hydrocodone with atazanavir may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of atazanavir could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If atazanavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Atazanavir is a strong inhibitor of CYP3A4. (Moderate) Concomitant use of hydrocodone with cobicistat may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of cobicistat could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Cobicistat is a strong inhibitor of CYP3A4 and also inhibits CYP2D6.
    Atenolol; Chlorthalidone: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Atracurium: (Moderate) Concomitant use of hydrocodone with other CNS depressants, such as neuromuscular blockers, can potentiate CNS and respiratory depression. A dose reduction of one or both drugs may be warranted.
    Atropine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Atropine; Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Atropine; Difenoxin: (Major) Concurrent administration of diphenoxylate/difenoxin with other opiate agonists can potentiate the CNS-depressant effects of diphenoxylate/difenoxin. Use caution during coadministration. In addition, diphenoxylate/difenoxin use may cause constipation; cases of severe GI reactions including toxic megacolon and adynamic ileus have been reported. Reduced GI motility when combined with opiate agonists may increase the risk of serious GI related adverse events. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Atropine; Diphenoxylate: (Major) Concurrent administration of diphenoxylate/difenoxin with other opiate agonists can potentiate the CNS-depressant effects of diphenoxylate/difenoxin. Use caution during coadministration. In addition, diphenoxylate/difenoxin use may cause constipation; cases of severe GI reactions including toxic megacolon and adynamic ileus have been reported. Reduced GI motility when combined with opiate agonists may increase the risk of serious GI related adverse events. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Atropine; Edrophonium: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Atropine; Hyoscyamine; Phenobarbital; Scopolamine: (Major) Concomitant use of hydrocodone with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when hydrocodone is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of hydrocodone with a barbiturate can decrease hydrocodone concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; hydrocodone is a CYP3A4 substrate. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
    Azelastine: (Major) Concomitant use of opioid agonists with azelastine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking azelastine. Limit the use of opioid pain medications with azelastine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Azelastine; Fluticasone: (Major) Concomitant use of opioid agonists with azelastine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking azelastine. Limit the use of opioid pain medications with azelastine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Azilsartan; Chlorthalidone: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Baclofen: (Major) Concomitant use of hydrocodone with a skeletal muscle relaxant may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients taking a skeletal muscle relaxant. Limit the use of opioid pain medications with a skeletal muscle relaxant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Barbiturates: (Major) Concomitant use of hydrocodone with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when hydrocodone is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of hydrocodone with a barbiturate can decrease hydrocodone concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; hydrocodone is a CYP3A4 substrate. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
    Belladonna Alkaloids; Ergotamine; Phenobarbital: (Major) Concomitant use of hydrocodone with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when hydrocodone is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of hydrocodone with a barbiturate can decrease hydrocodone concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; hydrocodone is a CYP3A4 substrate. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
    Belladonna; Opium: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Bendroflumethiazide; Nadolol: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Benzonatate: (Moderate) The vagal effects and respiratory depression induced by hydrocodone may be increased by the use of benzonatate.
    Benztropine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Bethanechol: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
    Bexarotene: (Moderate) Concomitant use of hydrocodone with bexarotene can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If bexarotene is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and bexarotene is a moderate CYP3A4 inducer.
    Bisacodyl: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as bisacodyl, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Bismuth Subcitrate Potassium; Metronidazole; Tetracycline: (Moderate) Additive constipation may be seen with concurrent use of opiate agonists and antidiarrheals. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Bismuth Subsalicylate: (Moderate) Additive constipation may be seen with concurrent use of opiate agonists and antidiarrheals. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. Although salicylates are rarely associated with nephrotoxicity, high-dose, chronic administration of salicylates combined other analgesics, including acetaminophen, significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Additive hepatic toxicity may occur, especially in combined overdose situations. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Additive constipation may be seen with concurrent use of opiate agonists and antidiarrheals. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. Although salicylates are rarely associated with nephrotoxicity, high-dose, chronic administration of salicylates combined other analgesics, including acetaminophen, significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Additive hepatic toxicity may occur, especially in combined overdose situations. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Boceprevir: (Major) Monitor for respiratory depression and sedation if hydrocodone and boceprevir are coadministered; consider dosage adjustments if necessary. Hydrocodone is metabolized by CYP3A4. Concomitant administration of a CYP3A4 inhibitor, such as boceprevir, may cause an increase in hydrocodone plasma concentrations, which could increase or prolong adverse effects. (Moderate) Close clinical monitoring is advised when administering acetaminophen with boceprevir due to an increased potential for acetaminophen-related adverse events. If acetaminophen 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 acetaminophen. Acetaminophen is partially metabolized by the hepatic isoenzyme CYP3A4; boceprevir inhibits this isoenzyme. Coadministration may result in elevated acetaminophen plasma concentrations.
    Bosentan: (Moderate) Concomitant use of hydrocodone with bosentan can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If bosentan is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and bosentan is a moderate CYP3A4 inducer.
    Brexpiprazole: (Moderate) Due to the CNS effects of brexpiprazole, caution is advisable when brexpiprazole is given in combination with other centrally-acting medications including opiate agonists.
    Brigatinib: (Moderate) Concomitant use of hydrocodone with brigatinib can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If brigatinib is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate. At clinically relevant concentrations, brigatinib induced CYP3A via activation of the pregnane X receptor (PXR); this may decrease concentrations of sensitive CYP3A substrates.
    Brimonidine: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of opiate agonists.
    Brimonidine; Brinzolamide: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of opiate agonists.
    Brimonidine; Timolol: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of opiate agonists.
    Brompheniramine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with brompheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Brompheniramine; Carbetapentane; Phenylephrine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with brompheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression. (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 morphine.
    Brompheniramine; Dextromethorphan; Guaifenesin: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with brompheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Brompheniramine; Guaifenesin; Hydrocodone: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with brompheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Brompheniramine; Hydrocodone; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with brompheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Brompheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with brompheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Bupivacaine Liposomal: (Moderate) Coadministration of bupivacaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue bupivacaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics 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. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Bupivacaine: (Moderate) Coadministration of bupivacaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue bupivacaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics 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. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Bupivacaine; Lidocaine: (Moderate) Coadministration of bupivacaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue bupivacaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) Coadministration of lidocaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue lidocaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics 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. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Buprenorphine: (Major) Buprenorphine is a mixed opiate agonist/antagonist with strong affinity for the mu-receptor that may partially block the effects of full mu-receptor opiate agonists and reduce analgesic effects. In some cases of acute pain, trauma, or during surgical management, opiate-dependent patients receiving buprenorphine maintenance therapy may require concurrent treatment with opiate agonists, such as hydrocodone. In these cases, health care professionals must exercise caution in opiate agonist dose selection, as higher doses of an opiate agonist may be required to compete with buprenorphine at the mu-receptor. Management strategies may include adding a short-acting opiate agonist to achieve analgesia in the presence of buprenorphine, discontinuation of buprenorphine and use of an opiate agonist to avoid withdrawal and achieve analgesia, or conversion of buprenorphine to methadone while using additional opiate agonists if needed. Closely monitor patients for CNS or respiratory depression. When buprenorphine is used for analgesia, avoid co-use with opiate agonists. Buprenorphine may cause withdrawal symptoms in patients receiving chronic opiate agonists as well as possibly potentiate CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
    Buprenorphine; Naloxone: (Major) Buprenorphine is a mixed opiate agonist/antagonist with strong affinity for the mu-receptor that may partially block the effects of full mu-receptor opiate agonists and reduce analgesic effects. In some cases of acute pain, trauma, or during surgical management, opiate-dependent patients receiving buprenorphine maintenance therapy may require concurrent treatment with opiate agonists, such as hydrocodone. In these cases, health care professionals must exercise caution in opiate agonist dose selection, as higher doses of an opiate agonist may be required to compete with buprenorphine at the mu-receptor. Management strategies may include adding a short-acting opiate agonist to achieve analgesia in the presence of buprenorphine, discontinuation of buprenorphine and use of an opiate agonist to avoid withdrawal and achieve analgesia, or conversion of buprenorphine to methadone while using additional opiate agonists if needed. Closely monitor patients for CNS or respiratory depression. When buprenorphine is used for analgesia, avoid co-use with opiate agonists. Buprenorphine may cause withdrawal symptoms in patients receiving chronic opiate agonists as well as possibly potentiate CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist. (Major) The opiate antagonists naloxone and naltrexone are pharmacologic opposites of hydrocodone. These drugs can block the actions of hydrocodone and, if administered to patients who have received chronic hydrocodone, can produce acute withdrawal and/or reduce the analgesic effect of hydrocodone.
    Bupropion: (Moderate) Concomitant use of hydrocodone with bupropion may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of bupropion could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If bupropion is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Bupropion is a strong inhibitor of CYP2D6.
    Bupropion; Naltrexone: (Major) The opiate antagonists naloxone and naltrexone are pharmacologic opposites of hydrocodone. These drugs can block the actions of hydrocodone and, if administered to patients who have received chronic hydrocodone, can produce acute withdrawal and/or reduce the analgesic effect of hydrocodone. (Moderate) Concomitant use of hydrocodone with bupropion may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of bupropion could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If bupropion is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Bupropion is a strong inhibitor of CYP2D6.
    Buspirone: (Moderate) Concomitant use of hydrocodone with other central nervous system depressants, such as buspirone, can potentiate the effects of hydrocodone and may lead to additive CNS or respiratory depression. If hydrocodone is used with buspirone, the dose of one or both drugs should be reduced.
    Busulfan: (Moderate) Use busulfan and acetaminophen together with caution; concomitant use may result in increased busulfan levels and increased busulfan toxicity. Separating the administration of these drugs may mitigate this interaction; avoid giving acetaminophen within 72 hours prior to or concurrently with busulfan. Busulfan is metabolized in the liver through conjugation with glutathione; acetaminophen decreases glutathione levels in the blood and tissues and may reduce the clearance of busulfan.
    Butabarbital: (Major) Concomitant use of hydrocodone with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when hydrocodone is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of hydrocodone with a barbiturate can decrease hydrocodone concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; hydrocodone is a CYP3A4 substrate. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
    Butorphanol: (Major) Avoid the concomitant use of butorphanol and opiate agonists, such as hydrocodone. Butorphanol is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of hydrocodone. Butorphanol may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of butorphanol with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
    Calcium Carbonate; Magnesium Hydroxide: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as magnesium hydroxide, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Cannabidiol: (Moderate) Concomitant use of opioid agonists with cannabidiol may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking cannabidiol. Limit the use of opioid pain medications with cannabidiol 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Capsaicin; Metaxalone: (Major) Concomitant use of hydrocodone with a skeletal muscle relaxant may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients taking a skeletal muscle relaxant. Limit the use of opioid pain medications with a skeletal muscle relaxant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Carbamazepine: (Moderate) Concomitant use of hydrocodone with carbamazepine can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If carbamazepine is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and carbamazepine is a strong CYP3A4 inducer. (Minor) Carbamazepine may potentially accelerate the hepatic metabolism of acetaminophen. In addition, due to enzyme induction, carbamazepine may increase the risk for acetaminophen-induced hepatotoxicity via generation of a greater percentage of acetaminophen's hepatotoxic metabolite, NAPQI. Clinicians should be alert to decreased effect of acetaminophen. Dosage adjustments may be necessary, and closer monitoring of clinical and/or adverse effects is warranted.
    Carbetapentane; Chlorpheniramine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression. (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 morphine.
    Carbetapentane; Chlorpheniramine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression. (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 morphine.
    Carbetapentane; Diphenhydramine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with diphenhydramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with diphenhydramine 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. Educate patients about the risks and symptoms of excessive CNS depression. (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 morphine.
    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 morphine.
    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 morphine.
    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 morphine.
    Carbetapentane; Phenylephrine; Pyrilamine: (Moderate) Concomitant use of opioid agonists with pyrilamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with pyrilamine 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. Educate patients about the risks and symptoms of excessive CNS depression. (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 morphine.
    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 morphine.
    Carbetapentane; Pyrilamine: (Moderate) Concomitant use of opioid agonists with pyrilamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with pyrilamine 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. Educate patients about the risks and symptoms of excessive CNS depression. (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 morphine.
    Carbinoxamine: (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carbinoxamine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Carbinoxamine; Dextromethorphan; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carbinoxamine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Carbinoxamine; Hydrocodone; Phenylephrine: (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carbinoxamine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Carbinoxamine; Hydrocodone; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carbinoxamine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Carbinoxamine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carbinoxamine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Carbinoxamine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carbinoxamine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Cariprazine: (Moderate) Due to the CNS effects of cariprazine, caution is advisable when cariprazine is given in combination with other centrally-acting medications including opiate agonists.
    Carisoprodol: (Major) Concomitant use of hydrocodone with a skeletal muscle relaxant may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients taking a skeletal muscle relaxant. Limit the use of opioid pain medications with a skeletal muscle relaxant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Castor Oil: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as castor oil, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Ceritinib: (Moderate) Concomitant use of hydrocodone with ceritinib may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of ceritinib could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If ceritinib is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. In vitro data suggests ceritinib is an inhibitor of CYP3A4.
    Cetirizine: (Moderate) Concomitant use of opioid agonists with cetirizine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with cetirizine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Cetirizine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with cetirizine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with cetirizine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Charcoal: (Minor) Activated charcoal binds many drugs within the gut. Administering charcoal dietary supplements at the same time as a routine acetaminophen dosage would be expected to interfere with the analgesic and antipyretic efficacy of acetaminophen. Charcoal is mostly used in the setting of acetaminophen overdose; however, patients should never try to treat an acetaminophen overdose with charcoal dietary supplements. Advise patients to get immediate medical attention for an acetaminophen overdose.
    Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with dexchlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with dexchlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chloral Hydrate: (Major) Concomitant use of opioid agonists with chloral hydrate may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking chloral hydrate. Limit the use of opioid pain medications with chloral hydrate 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chloramphenicol: (Moderate) Concomitant use of hydrocodone with chloramphenicol may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of chloramphenicol could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If chloramphenicol is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Chloramphenicol is a strong inhibitor of CYP3A4.
    Chlorcyclizine: (Moderate) Concomitant use of opioid agonists with chlorcyclizine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorcyclizine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlordiazepoxide: (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.
    Chlordiazepoxide; Clidinium: (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) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Chloroprocaine: (Moderate) Coadministration of chloroprocaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue chloroprocaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Minor) Due to the CNS depression potential of all local anesthetics, they should be used with caution with other agents that can cause respiratory depression, such as opiate agonists.
    Chlorothiazide: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Chlorpheniramine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Codeine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Dextromethorphan: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Dihydrocodeine; Pseudoephedrine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Guaifenesin; Hydrocodone; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Hydrocodone: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Hydrocodone; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Hydrocodone; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorpromazine: (Major) Concomitant use of opioid agonists with chlorpromazine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking chlorpromazine. Limit the use of opioid pain medications with chlorpromazine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Chlorthalidone: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Chlorthalidone; Clonidine: (Moderate) Clonidine has CNS depressive effects and can potentiate the actions of other CNS depressants including opiate agonists. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Chlorzoxazone: (Major) Concomitant use of hydrocodone with a skeletal muscle relaxant may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients taking a skeletal muscle relaxant. Limit the use of opioid pain medications with a skeletal muscle relaxant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Cholestyramine: (Moderate) Cholestyramine has been shown to decrease the absorption of acetaminophen by roughly 60%. Experts have recommended that cholestyramine not be given within 1 hour of acetaminophen if analgesic or antipyretic effect is to be achieved.
    Choline Salicylate; Magnesium Salicylate: (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. Although salicylates are rarely associated with nephrotoxicity, high-dose, chronic administration of salicylates combined other analgesics, including acetaminophen, significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Additive hepatic toxicity may occur, especially in combined overdose situations. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
    Cimetidine: (Minor) Concurrent use may increase the adverse effects of hydrocodone, especially if a large cimetidine dose ( more than 600 mg/day) is used or if the patient is not young and healthy. The clinical significance of this interaction is not established. Monitor patients for increased respiratory and CNS depression.
    Cinacalcet: (Moderate) Concomitant use of hydrocodone with cinacalcet may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of cinacalcet could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If cinacalcet is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Cinacalcet is a strong inhibitor of CYP2D6.
    Ciprofloxacin: (Moderate) Concomitant use of hydrocodone with ciprofloxacin may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of ciprofloxacin could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If ciprofloxacin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Ciprofloxacin is a moderate inhibitor of CYP3A4.
    Cisatracurium: (Moderate) Concomitant use of hydrocodone with other CNS depressants, such as neuromuscular blockers, can potentiate CNS and respiratory depression. A dose reduction of one or both drugs may be warranted.
    Citalopram: (Major) Because of the potential risk and severity of serotonin syndrome, caution and careful monitoring are recommended when administering selective serotonin reuptake inhibitors (SSRIs), such as citalopram, with other drugs that have serotonergic properties such as codeine. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. codeine and citalopram should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Clarithromycin: (Moderate) Concomitant use of hydrocodone with clarithromycin may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of clarithromycin could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If clarithromycin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Clarithromycin is a strong inhibitor of CYP3A4.
    Clemastine: (Moderate) Concomitant use of opioid agonists with clemastine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with clemastine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Clobazam: (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. Additionally, the metabolism of hydrocodone to its active metabolite, hydromorphone, is dependent on CYP2D6. Theoretically, co-administration of hydrocodone and a CYP2D6 inhibitor, such as clobazam, may result in a reduction in the analgesic effect of hydrocodone. Avoid opiate cough medications in patients taking benzodiazepines.
    Clonazepam: (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.
    Clonidine: (Moderate) Clonidine has CNS depressive effects and can potentiate the actions of other CNS depressants including opiate agonists.
    Clopidogrel: (Moderate) Coadministration of opioid agonists delay and reduce the absorption of clopidogrel resulting in reduced exposure to active metabolites and diminished inhibition of platelet aggregation. Consider the use of a parenteral antiplatelet agent in acute coronary syndrome patients requiring an opioid agonist. Coadministration of intravenous morphine decreased the Cmax and AUC of clopidogrel's active metabolites by 34%. Time required for maximal inhibition of platelet aggregation (median 3 hours vs. 1.25 hours) was significantly delayed; times up to 5 hours were reported. Inhibition of platelet plug formation was delayed and residual platelet aggregation was significantly greater 1 to 4 hours after morphine administration.
    Clorazepate: (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.
    Clozapine: (Moderate) Concomitant use of hydrocodone with other CNS depressants, such as clozapine, may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. In addition, combining clozapine with opiate agonists may lead to additive effects on intestinal motility or bladder function.
    Cobicistat: (Moderate) Concomitant use of hydrocodone with cobicistat may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of cobicistat could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Cobicistat is a strong inhibitor of CYP3A4 and also inhibits CYP2D6.
    Cobicistat; Elvitegravir; Emtricitabine; Tenofovir Alafenamide: (Moderate) Concomitant use of hydrocodone with cobicistat may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of cobicistat could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Cobicistat is a strong inhibitor of CYP3A4 and also inhibits CYP2D6.
    Cobicistat; Elvitegravir; Emtricitabine; Tenofovir Disoproxil Fumarate: (Moderate) Concomitant use of hydrocodone with cobicistat may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of cobicistat could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Cobicistat is a strong inhibitor of CYP3A4 and also inhibits CYP2D6.
    Codeine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
    Codeine; Guaifenesin: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
    Codeine; Phenylephrine; Promethazine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Major) Concomitant use of opioid agonists with promethazine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking promethazine. Limit the use of opioid pain medications with promethazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce the opioid dose by one-quarter to one-half; use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
    Codeine; Promethazine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Major) Concomitant use of opioid agonists with promethazine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking promethazine. Limit the use of opioid pain medications with promethazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce the opioid dose by one-quarter to one-half; use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
    COMT inhibitors: (Major) Concomitant use of opioid agonists with COMT inhibitors may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking COMT inhibitors. Limit the use of opioid pain medications with COMT inhibitors 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. Educate patients about the risks and symptoms of excessive CNS depression. Dopaminergic agents like entacapone and tolcapone have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment.
    Conivaptan: (Moderate) Concomitant use of hydrocodone with conivaptan may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of conivaptan could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If conivaptan is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Conivaptan is a strong inhibitor of CYP3A4.
    Crizotinib: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of crizotinib is necessary. It is recommended to avoid this combination when hydrocodone is being used for cough. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like crizotinib can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If crizotinib is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
    Crofelemer: (Moderate) Pharmacodynamic interactions between crofelemer and opiate agonists are theoretically possible. Crofelemer does not affect GI motility mechanisms, but does have antidiarrheal effects. Patients taking medications that decrease GI motility, such as opiate agonists, may be at greater risk for serious complications from crofelemer, such as constipation with chronic use. Use caution and monitor GI symptoms during coadministration.
    Cyclizine: (Moderate) Concomitant use of opioid agonists with cyclizine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with cyclizine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Cyclobenzaprine: (Major) Concomitant use of hydrocodone with a skeletal muscle relaxant may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients taking a skeletal muscle relaxant. Limit the use of opioid pain medications with a skeletal muscle relaxant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Cyclosporine: (Moderate) Concomitant use of hydrocodone with cyclosporine may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of cyclosporine could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If cyclosporine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Cyclosporine is a moderate inhibitor of CYP3A4.
    Cyproheptadine: (Moderate) Concomitant use of opioid agonists with cyproheptadine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with cyproheptadine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Dabrafenib: (Moderate) Concomitant use of hydrocodone with dabrafenib can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If dabrafenib is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and dabrafenib is a moderate CYP3A4 inducer.
    Dacomitinib: (Moderate) Concomitant use of hydrocodone with dacomitinib may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of dacomitinib could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If dacomitinib is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Dacomitinib is a strong inhibitor of CYP2D6.
    Dalfopristin; Quinupristin: (Moderate) Concomitant use of hydrocodone with dalfopristin; quinupristin may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of dalfopristin; quinupristin could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If dalfopristin; quinupristin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Dalfopristin; quinupristin is a weak inhibitor of CYP3A4.
    Danazol: (Moderate) Concomitant use of hydrocodone with danazol may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of danazol could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If danazol is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Danazol is a moderate inhibitor of CYP3A4.
    Dantrolene: (Major) Concomitant use of hydrocodone with a skeletal muscle relaxant may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients taking a skeletal muscle relaxant. Limit the use of opioid pain medications with a skeletal muscle relaxant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Darifenacin: (Moderate) Concomitant use of hydrocodone with darifenacin may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including a risk for hypotension, respiratory depression, profound sedation, coma, and death. Avoid use of hydrocodone when it is being used for cough; consider alternative agents for cough treatment. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of darifenacin could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If darifenacin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Darifenacin is a moderate inhibitor of CYP2D6. In addition, the concomitant use of these drugs together may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Darifenacin has anticholinergic actions that may produce additive effects. Both agents may also cause drowsiness or blurred vision, and patients should use care in driving or performing other hazardous tasks until the effects of the drugs are known.
    Darunavir: (Moderate) Concomitant use of hydrocodone with darunavir may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of darunavir could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If darunavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Darunavir is a strong inhibitor of CYP3A4.
    Darunavir; Cobicistat: (Moderate) Concomitant use of hydrocodone with cobicistat may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of cobicistat could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Cobicistat is a strong inhibitor of CYP3A4 and also inhibits CYP2D6. (Moderate) Concomitant use of hydrocodone with darunavir may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of darunavir could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If darunavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Darunavir is a strong inhibitor of CYP3A4.
    Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Moderate) Concomitant use of hydrocodone with cobicistat may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of cobicistat could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Cobicistat is a strong inhibitor of CYP3A4 and also inhibits CYP2D6. (Moderate) Concomitant use of hydrocodone with darunavir may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of darunavir could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If darunavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Darunavir is a strong inhibitor of CYP3A4.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Concomitant use of hydrocodone with ritonavir may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of ritonavir could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If ritonavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Ritonavir is a strong inhibitor of CYP3A4 and also inhibits CYP2D6. (Moderate) Concurrent administration of acetaminophen with ritonavir may result in elevated acetaminophen plasma concentrations and subsequent adverse events. Acetaminophen is metabolized by the hepatic isoenzyme CYP3A4; ritonavir is an inhibitor of this enzyme. Caution and close monitoring are advised if these drugs are administered together.
    Deferasirox: (Moderate) Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal if coadministration with deferasirox is necessary; consider increasing the dose of hydrocodone as needed. If deferasirox is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and deferasirox is a weak CYP3A4 inducer. Concomitant use with CYP3A4 inducers can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
    Delavirdine: (Moderate) Concomitant use of hydrocodone with delavirdine may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of delavirdine could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If delavirdine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Delavirdine is a strong inhibitor of CYP3A4 and a moderate inhibitor of CYP2D6.
    Desflurane: (Moderate) Concurrent use with opiate agonists can decrease the minimum alveolar concentration (MAC) of desflurane needed to produce anesthesia.
    Desmopressin: (Major) Additive hyponatremic effects may be seen in patients treated with desmopressin and drugs associated with water intoxication, hyponatremia, or SIADH including opiate agonists. Use combination with caution, and monitor patients for signs and symptoms of hyponatremia.
    Desvenlafaxine: (Major) Careful monitoring, particularly during treatment initiation and dose adjustment, is recommended during coadministration of hydrocodone and desvenlafaxine because of the potential risk of serotonin syndrome. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. Discontinue hydrocodone if serotonin syndrome is suspected. Additionally, concomitant use of hydrocodone with desvenlafaxine may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of desvenlafaxine could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If desvenlafaxine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Desvenlafaxine is a weak inhibitor of CYP2D6.
    Deutetrabenazine: (Major) Concomitant use of opiate agonists with deutetrabenazine may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with deutetrabenazine 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen are initiated in a patient taking deutetrabenazine, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tabIets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If deutetrabenazine is prescribed for a patient taking an opiate agonist, use a lower initial dose of deutetrabenazine 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 deutetrabenazine.
    Dexamethasone: (Moderate) Concomitant use of hydrocodone with dexamethasone can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If dexamethasone is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and dexamethasone is a moderate CYP3A4 inducer.
    Dexchlorpheniramine: (Moderate) Concomitant use of opioid agonists with dexchlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with dexchlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with dexchlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with dexchlorpheniramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Dexmedetomidine: (Moderate) Co-administration of dexmedetomidine with opiate agonists likely to lead to an enhancement of CNS depression.
    Dexpanthenol: (Moderate) Use caution when using dexpanthenol with drugs that decrease gastrointestinal motility, such as opiate agonists, as it may decrease the effectiveness of dexpanthenol.
    Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with diphenhydramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with diphenhydramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Dextromethorphan; Promethazine: (Major) Concomitant use of opioid agonists with promethazine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking promethazine. Limit the use of opioid pain medications with promethazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce the opioid dose by one-quarter to one-half; use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
    Dextromethorphan; Quinidine: (Moderate) Concomitant use of hydrocodone with quinidine may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of quinidine could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If quinidine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Quinidine is a strong inhibitor of CYP2D6.
    Diazepam: (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. If parental diazepam is used with an opiate agonist, reduce the opiate agonist dosage by at least 1/3. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid opiate cough medications in patients taking benzodiazepines.
    Dicyclomine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Diflunisal: (Moderate) Acetaminophen plasma concentrations can increase by approximately 50% following administration of diflunisal. Acetaminophen has no effect on diflunisal concentrations. Acetaminophen in high doses has been associated with severe hepatotoxic reactions; therefore, caution should be exercised when using these agents concomitantly.
    Dihydrocodeine; Guaifenesin; Pseudoephedrine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
    Diltiazem: (Moderate) Concomitant use of hydrocodone with diltiazem may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of diltiazem could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If diltiazem is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Diltiazem is a moderate inhibitor of CYP3A4.
    Dimenhydrinate: (Moderate) Concomitant use of opioid agonists with dimenhydrinate may cause excessive sedation and somnolence. Limit the use of opioid pain medications with dimenhydrinate 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Diphenhydramine: (Moderate) Concomitant use of opioid agonists with diphenhydramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with diphenhydramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Diphenhydramine; Hydrocodone; Phenylephrine: (Moderate) Concomitant use of opioid agonists with diphenhydramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with diphenhydramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Diphenhydramine; Ibuprofen: (Moderate) Concomitant use of opioid agonists with diphenhydramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with diphenhydramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Diphenhydramine; Naproxen: (Moderate) Concomitant use of opioid agonists with diphenhydramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with diphenhydramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Diphenhydramine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with diphenhydramine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with diphenhydramine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Dolasetron: (Major) Because of the potential risk and severity of serotonin syndrome, caution and careful monitoring are recommended when coadministering serotonin-receptor antagonists with other drugs that have serotonergic properties such as hydrocodone. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Hydrocodone and the serotonin-receptor antagonist should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Doxacurium: (Moderate) Concomitant use of hydrocodone with other CNS depressants, such as neuromuscular blockers, can potentiate CNS and respiratory depression. A dose reduction of one or both drugs may be warranted.
    Doxylamine: (Moderate) Concomitant use of opioid agonists with doxylamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with doxylamine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Doxylamine; Pyridoxine: (Moderate) Concomitant use of opioid agonists with doxylamine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with doxylamine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Dronabinol: (Moderate) Concomitant use of opiate agonists and other CNS depressants such as dronabinol, THC may result in respiratory depression, CNS depression, and/or hypotension. Prior to concurrent use of opiate agonists in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. When concomitant treatment is necessary, reduce the dose of 1 or both drugs. When levorphanol is used with dronabinol, reduce the initial levorphanol dose by approximately 50% or more.
    Dronedarone: (Moderate) Concomitant use of hydrocodone with dronedarone may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of dronedarone could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If dronedarone is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Dronedarone is a moderate inhibitor of CYP3A4 and CYP2D6.
    Droperidol: (Major) Concomitant use of opioid agonists with droperidol may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking droperidol. Limit the use of opioid pain medications with droperidol 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Drospirenone; Ethinyl Estradiol: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Drospirenone; Ethinyl Estradiol; Levomefolate: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Duloxetine: (Major) Careful monitoring, particularly during treatment initiation and dose adjustment, is recommended during coadministration of hydrocodone and duloxetine because of the potential risk of serotonin syndrome and prolonged opioid adverse reactions. Discontinue hydrocodone if serotonin syndrome is suspected. It is recommended to avoid this combination when hydrocodone is being used for cough. Concomitant use of hydrocodone with duloxetine may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. Monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of duloxetine could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If duloxetine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Duloxetine is a moderate inhibitor of CYP2D6. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
    Efavirenz: (Moderate) Concomitant use of hydrocodone with efavirenz can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If efavirenz is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and efavirenz is a moderate CYP3A4 inducer. (Minor) Drugs that induce the hepatic isoenzymes CYP2E1 and CYP1A2, such as efavirenz, may potentially increase the risk for acetaminophen-induced hepatotoxicity via generation of a greater percentage of acetaminophen's hepatotoxic metabolite, NAPQI. Also, the analgesic activity of acetaminophen may be reduced.
    Efavirenz; Emtricitabine; Tenofovir: (Moderate) Concomitant use of hydrocodone with efavirenz can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If efavirenz is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and efavirenz is a moderate CYP3A4 inducer. (Minor) Drugs that induce the hepatic isoenzymes CYP2E1 and CYP1A2, such as efavirenz, may potentially increase the risk for acetaminophen-induced hepatotoxicity via generation of a greater percentage of acetaminophen's hepatotoxic metabolite, NAPQI. Also, the analgesic activity of acetaminophen may be reduced.
    Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Moderate) Concomitant use of hydrocodone with efavirenz can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If efavirenz is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and efavirenz is a moderate CYP3A4 inducer. (Minor) Drugs that induce the hepatic isoenzymes CYP2E1 and CYP1A2, such as efavirenz, may potentially increase the risk for acetaminophen-induced hepatotoxicity via generation of a greater percentage of acetaminophen's hepatotoxic metabolite, NAPQI. Also, the analgesic activity of acetaminophen may be reduced.
    Elagolix: (Moderate) Concomitant use of hydrocodone with elagolix can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If elagolix is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and elagolix is a weak to moderate CYP3A4 inducer.
    Elbasvir; Grazoprevir: (Moderate) Administering hydrocodone with elbasvir; grazoprevir may result in elevated hydrocodone plasma concentrations. Hydrocodone is a substrate of CYP3A; grazoprevir is a weak CYP3A inhibitor. If these drugs are used together, closely monitor for signs of adverse events.
    Eletriptan: (Major) Because of the potential risk and severity of serotonin syndrome, caution and careful monitoring are recommended when administering serotonin-receptor agonists with other drugs that have serotonergic properties such as opioids. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Hydrocodone and the serotonin-receptor agonist should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Eliglustat: (Moderate) Concomitant use of hydrocodone with eliglustat may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of eliglustat could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If eliglustat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Eliglustat is a moderate inhibitor of CYP2D6.
    Eltrombopag: (Moderate) Eltrombopag is a UDP-glucuronyltransferase inhibitor. Acetaminophen is a substrate of UDP-glucuronyltransferases. The significance or effect of this interaction is not known; however, elevated concentrations of acetaminophen are possible. Monitor patients for adverse reactions if these drugs are coadministered. (Moderate) Eltrombopag is a UDP-glucuronyltransferase inhibitor. Opiate agonists are a substrate of UDP-glucuronyltransferases. The significance or effect of this interaction is not known; however, elevated concentrations of the opiate agonist is possible. Monitor patients for adverse reactions if eltrombopage is administered with an opiate agonist.
    Eluxadoline: (Major) Avoid use of eluxadoline with medications that may cause constipation, such as hydrocodone. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle within the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. Closely monitor for increased side effects if these drugs are administered together.
    Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Enflurane: (Major) Concomitant use of hydrocodone with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients receiving a general anesthetic. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Enzalutamide: (Moderate) Concomitant use of hydrocodone with enzalutamide can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If enzalutamide is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and enzalutamide is a strong CYP3A4 inducer.
    Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Erythromycin: (Moderate) Concomitant use of hydrocodone with erythromycin may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation oferythromycin could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. Iferythromycin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Erythromycin is a moderate inhibitor of CYP3A4.
    Erythromycin; Sulfisoxazole: (Moderate) Concomitant use of hydrocodone with erythromycin may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation oferythromycin could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. Iferythromycin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Erythromycin is a moderate inhibitor of CYP3A4.
    Escitalopram: (Major) Careful monitoring, particularly during treatment initiation and dose adjustment, is recommended during coadministration of hydrocodone and escitalopram because of the potential risk of serotonin syndrome. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. Discontinue hydrocodone if serotonin syndrome is suspected. Additionally, concomitant use of hydrocodone with escitalopram may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of escitalopram could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If escitalopram is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Escitalopram is a weak inhibitor of CYP2D6.
    Eslicarbazepine: (Moderate) Concomitant use of hydrocodone with eslicarbazepine can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If eslicarbazepine is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and eslicarbazepine is a moderate CYP3A4 inducer.
    Estazolam: (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.
    Eszopiclone: (Major) Concomitant use of opioid agonists with eszopiclone may cause excessive sedation, somnolence, and complex sleep-related behaviors (e.g., driving, talking, eating, or performing other activities while not fully awake). Avoid prescribing opioid cough medications in patients taking eszopiclone. Limit the use of opioid pain medications with eszopiclone 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. Instruct patients to contact their provider immediately if sleep-related symptoms or behaviors occur. Educate patients about the risks and symptoms of excessive CNS depression.
    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. (Major) The risk of developing hepatotoxicity from acetaminophen appears to be increased in patients who regularly consume ethanol. Patients who drink more than 3 alcoholic drinks a day and take acetaminophen are at increased risk of developing hepatotoxicity. Acute or chronic ethanol use increases acetaminophen-induced hepatotoxicity by inducing cytochrome P450 CYP 2E1 leading to increased formation of the hepatotoxic metabolite of acetaminophen. Also, chronic alcohol use can deplete liver glutathione stores. Administration of acetaminophen should be limited or avoided altogether in patients with alcoholism or patients who consume ethanol regularly.
    Ethinyl Estradiol: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Desogestrel: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Ethynodiol Diacetate: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Etonogestrel: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Levonorgestrel: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Levonorgestrel; Ferrous bisglycinate: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Levonorgestrel; Folic Acid; Levomefolate: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Norelgestromin: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Norethindrone Acetate: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Norethindrone Acetate; Ferrous fumarate: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Norethindrone: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Norethindrone; Ferrous fumarate: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Norgestimate: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Ethinyl Estradiol; Norgestrel: (Moderate) Acetaminophen may increase plasma ethinyl estradiol levels, possibly by inhibition of conjugation. Patients taking acetaminophen concomitantly may experience an increase in estrogen related side effects.
    Etomidate: (Major) Concomitant use of hydrocodone with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients receiving a general anesthetic. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Etravirine: (Moderate) Concomitant use of hydrocodone with etravirine can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If etravirine is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and etravirine is a moderate CYP3A4 inducer.
    Everolimus: (Moderate) Monitor for an increase in hydrocodone-related adverse reactions, including sedation and respiratory depression, if coadministration with everolimus is necessary; consider reducing the dose of hydrocodone if clinically appropriate. If everolimus is discontinued, monitor for evidence of opioid withdrawal until stable drug effects are achieved and consider increasing the hydrocodone dose if necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with weak CYP3A4 inhibitors like everolimus can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If everolimus is discontinued, hydrocodone plasma concentrations may decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
    Exenatide: (Minor) Although an interaction is possible, these drugs may be used together. To avoid potential pharmacokinetic interactions that might alter effectiveness of acetaminophen, it may be advisable for patients to take acetaminophen at least 1 hour prior to an exenatide injection. When 1,000 mg acetaminophen elixir was given with 10 mcg exenatide (at 0 hours) and at 1, 2 and 4 hours after exenatide injection, acetaminophen AUCs were decreased by 21%, 23%, 24%, and 14%, respectively; Cmax was decreased by 37%, 56%, 54%, and 41%, respectively. Additionally, acetaminophen Tmax was delayed from 0.6 hours in the control period to 0.9, 4.2, 3.3, and 1.6 hours, respectively. Acetaminophen AUC, Cmax, and Tmax were not significantly changed when acetaminophen was given 1 h before exenatide injection. The mechanism of this interaction is not available (although it may be due to delayed gastric emptying from exenatide use) and the clinical impact has not been assessed.
    Fentanyl: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
    Fesoterodine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when fesoterodine, an anticholinergic drug for overactive bladder. is used with opiate agonists. The concomitant use of these drugs together may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. Both agents may also cause drowsiness or blurred vision, and patients should use care in driving or performing other hazardous tasks until the effects of the drugs are known.
    Flavoxate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Flibanserin: (Moderate) The concomitant use of flibanserin with CNS depressants, such as opiate agonists, may increase the risk of CNS depression (e.g., dizziness, somnolence) compared to the use of flibanserin alone. Patients should avoid activities requiring full alertness (e.g., operating machinery or driving) until at least 6 hours after each dose and until they know how flibanserin affects them.
    Fluconazole: (Moderate) Concomitant use of hydrocodone with fluconazole may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of fluconazole could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If fluconazole is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Fluconazole is a moderate inhibitor of CYP3A4.
    Fluoxetine: (Major) Careful monitoring, particularly during treatment initiation and dose adjustment, is recommended during coadministration of hydrocodone and fluoxetine because of the potential risk of serotonin syndrome and prolonged opioid adverse reactions. Discontinue hydrocodone if serotonin syndrome is suspected. It is recommended to avoid this combination when hydrocodone is being used for cough. Concomitant use of hydrocodone with fluoxetine may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. Monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of fluoxetine could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If fluoxetine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Fluoxetine is a strong inhibitor of CYP2D6. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
    Fluoxetine; Olanzapine: (Major) Careful monitoring, particularly during treatment initiation and dose adjustment, is recommended during coadministration of hydrocodone and fluoxetine because of the potential risk of serotonin syndrome and prolonged opioid adverse reactions. Discontinue hydrocodone if serotonin syndrome is suspected. It is recommended to avoid this combination when hydrocodone is being used for cough. Concomitant use of hydrocodone with fluoxetine may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. Monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of fluoxetine could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If fluoxetine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Fluoxetine is a strong inhibitor of CYP2D6. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. (Moderate) Concomitant use of hydrocodone with other CNS depressants like olanzapine may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking olanzapine, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also, consider using a lower dose of olanzapine. Monitor patients for sedation and respiratory depression.
    Fluphenazine: (Moderate) Concomitant use of opioid agonists with fluphenazine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking fluphenazine. Limit the use of opioid pain medications with fluphenazine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Flurazepam: (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.
    Flutamide: (Moderate) Hydrocodone is metabolized by CYP3A4. Flutamide, an inducer of CYP3A4, may cause increased clearance of hydrocodone, which could result in lack of efficacy or the development of an abstinence syndrome in a patient who had developed physical dependence to hydrocodone. Monitor the patient for reduced efficacy of hydrocodone. A higher hydrocodone dose may be needed if used with flutamide.
    Fluvoxamine: (Major) Careful monitoring, particularly during treatment initiation and dose adjustment, is recommended during coadministration of hydrocodone and fluvoxamine because of the potential risk of serotonin syndrome and prolonged opioid adverse reactions. Discontinue hydrocodone if serotonin syndrome is suspected. It is recommended to avoid this combination when hydrocodone is being used for cough. Concomitant use of hydrocodone with fluvoxamine may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. Monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of fluvoxamine could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If fluvoxamine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Fluvoxamine is a moderate inhibitor of CYP3A4. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
    Fosamprenavir: (Moderate) Concomitant use of hydrocodone with fosamprenavir may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of fosamprenavir could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If fosamprenavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Fosamprenavir is a strong inhibitor of CYP3A4.
    Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Fosphenytoin: (Moderate) Concomitant use of hydrocodone with fosphenytoin can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If fosphenytoin is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and phenytoin (the active metabolite of fosphenytoin) is a strong CYP3A4 inducer.
    Fospropofol: (Major) Concomitant use of hydrocodone with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients receiving a general anesthetic. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Fostamatinib: (Moderate) Monitor for hydrocodone toxicities that may require hydrocodone dose reduction if given concurrently with fostamatinib. Concomitant use of fostamatinib with a CYP3A4 substrate may increase the concentration of the CYP3A4 substrate. The active metabolite of fostamatinib, R406, is a CYP3A4 inhibitor; hydrocodone is a substrate for CYP3A4. Coadministration of fostamatinib with a sensitive CYP3A4 substrate increased the substrate AUC by 64% and Cmax by 113%.
    Frovatriptan: (Major) Because of the potential risk and severity of serotonin syndrome, caution and careful monitoring are recommended when administering serotonin-receptor agonists with other drugs that have serotonergic properties such as opioids. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Hydrocodone and the serotonin-receptor agonist should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Gabapentin: (Moderate) Concomitant use of opioid agonists with gabapentin may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking gabapentin. Limit the use of opioid pain medications with gabapentin 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. Educate patients about the risks and symptoms of excessive CNS depression.
    General anesthetics: (Major) Concomitant use of hydrocodone with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients receiving a general anesthetic. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Glycopyrrolate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Glycopyrrolate; Formoterol: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Granisetron: (Major) Because of the potential risk and severity of serotonin syndrome, caution and careful monitoring are recommended when coadministering serotonin-receptor antagonists with other drugs that have serotonergic properties such as hydrocodone. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Hydrocodone and the serotonin-receptor antagonist should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Grapefruit juice: (Moderate) Patients should not significantly alter their intake of grapefruit or grapefruit juice during therapy with hydrocodone. Grapefruit juice, a CYP3A4 inhibitor, may increase plasma concentrations of hydrocodone, a CYP3A4 substrate. This may increase or prolong hydrocodone-related toxicities including respiratory depression. Advise patients accordingly; patient monitoring and dosage adjustments may be necessary if grapefruit is consumed regularly.
    Guanabenz: (Moderate) Guanabenz is associated with sedative effects. Guanabenz can potentiate the effects of CNS depressants such as opiate agonists, when administered concomitantly.
    Guanfacine: (Moderate) Central-acting adrenergic agonists like guanfacine have CNS depressive effects and can potentiate the actions of other CNS depressants including opiate agonists.
    Haloperidol: (Moderate) Concomitant use of hydrocodone with haloperidol may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of haloperidol could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If haloperidol is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Haloperidol is a moderate inhibitor of CYP2D6.
    Halothane: (Major) Concomitant use of hydrocodone with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients receiving a general anesthetic. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Homatropine; Hydrocodone: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Hydantoins: (Minor) Hydantoin anticonvulsants induce hepatic microsomal enzymes and may increase the metabolism of other drugs, leading to reduced efficacy of medications like acetaminophen. In addition, the risk of hepatotoxicity from acetaminophen may be increased with the chronic dosing of acetaminophen along with phenytoin. Adhere to recommended acetaminophen dosage limits. Acetaminophen-related hepatotoxicity has occurred clinically with the concurrent use of acetaminophen 1300 mg to 6200 mg daily and phenytoin. Acetaminophen cessation led to serum transaminase normalization within 2 weeks.
    Hydralazine; Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Irbesartan: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Lisinopril: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Losartan: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Methyldopa is associated with sedative effects. Methyldopa can potentiate the effects of CNS depressants, such as opiate agonists, when administered concomitantly. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Metoprolol: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Olmesartan: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Propranolol: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Quinapril: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Spironolactone: (Moderate) Opiate agonists like hydrocodone may potentiate orthostatic hypotension when given concomitantly with spironolactone. (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Telmisartan: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Triamterene: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydrochlorothiazide, HCTZ; Valsartan: (Moderate) Opiate agonists may potentiate orthostatic hypotension when used concurrently with thiazide diuretics.
    Hydromorphone: (Major) Concomitant use of hydromorphone with other central nervous system (CNS) depressants, such as other opiate agonists like hydrocodone, can potentiate the effects of hydromorphone and may lead to additive CNS or respiratory depression, profound sedation, or coma. Prior to concurrent use of hydromorphone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. If hydromorphone is used concurrently with a CNS depressant, a reduced dosage of hydromorphone and/or the CNS depressant is recommended; start with one-third to one-half of the estimated hydromorphone starting dose when using hydromorphone extended-release tablets. Carefully monitor the patient for hypotension, CNS depression, and respiratory depression. Carbon dioxide retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids.
    Hydroxychloroquine: (Moderate) Concomitant use of hydrocodone with hydroxychloroquine may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of hydroxychloroquine could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If hydroxychloroquine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP2D6. Hydroxychloroquine is a moderate inhibitor of CYP2D6.
    Hydroxyprogesterone: (Moderate) In vitro studies indicate that hydroxyprogesterone increases the metabolic rate of CYP2A6 isoenzymes. The metabolism of drugs metabolized by CYP2A6, such as acetaminophen may be increased during treatment with hydroxyprogesterone.
    Hydroxyzine: (Major) Concomitant use of opioid agonists with hydroxyzine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with hydroxyzine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Hyoscyamine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Ibuprofen; Oxycodone: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. Monitor patients for sedation and respiratory depression.
    Idelalisib: (Moderate) Concomitant use of hydrocodone with idelalisib may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of idelalisib could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If idelalisib is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Idelalisib is a strong inhibitor of CYP3A4.
    Iloperidone: (Moderate) Concomitant use of iloperidone with other centrally-acting medications such as opiate agonists, may increase both the frequency and the intensity of adverse effects including drowsiness, sedation, and dizziness.
    Imatinib: (Major) Imatinib, STI-571 may affect the metabolism of acetaminophen. In vitro, imatinib was found to inhibit acetaminophen O-glucuronidation at therapeutic levels. Therefore, systemic exposure to acetaminophen is expected to be increased with coadministration of imatinib. Chronic acetaminophen therapy should be avoided in patients receiving imatinib. (Moderate) Concomitant use of hydrocodone with imatinib may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of imatinib could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If imatinib is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4 and CYP2D6. Imatinib is a moderate inhibitor of CYP3A4 and is also an inhibitor of CYP2D6.
    Indacaterol; Glycopyrrolate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when hydrocodone is used concomitantly with an anticholinergic drug. The concomitant use of hydrocodone and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Indinavir: (Moderate) Concomitant use of hydrocodone with indinavir may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of indinavir could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If indinavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Indinavir is a strong inhibitor of CYP3A4.
    Insulin Glargine; Lixisenatide: (Minor) When 1,000 mg acetaminophen was given 1 or 4 hours after 10 mcg lixisenatide, the AUC was not significantly changed, but the acetaminophen Cmax was decreased by 29% and 31%, respectively and median Tmax was delayed by 2 and 1.75 hours, respectively. Acetaminophen AUC, Cmax, and Tmax were not significantly changed when acetaminophen was given 1 h before lixisenatide injection. The mechanism of this interaction is not available (although it may be due to delayed gastric emptying) and the clinical impact has not been assessed. To avoid potential pharmacokinetic interactions that might alter effectiveness of acetaminophen, it may be advisable for patients to take acetaminophen at least one hour prior to lixisenatide subcutaneous injection.
    Isavuconazonium: (Moderate) Concomitant use of hydrocodone with isavuconazonium may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of isavuconazonium could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If isavuconazonium is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Isavuconazonium is a moderate inhibitor of CYP3A4. (Moderate) Concomitant use of isavuconazonium with acetaminophen may result in increased serum concentrations of acetaminophen. Acetaminophen is a substrate of the hepatic isoenzyme CYP3A4; isavuconazole, the active moiety of isavuconazonium, is a moderate inhibitor of this enzyme. Caution and close monitoring are advised if these drugs are used together.
    Isocarboxazid: (Major) Hydrocodone is not recommended for use in patients who have received MAOIs within 14 days. Certain products are contraindicated due to the risk: benefit ratio (e.g., hydrocodone-containing cough syrups). Consider if an alternative to the hydrocodone-containing product is available and appropriate. Severe and unpredictable potentiation by MAO inhibitors has been reported with opioid analgesics. Also, potentiation of the effects of the MAOI have been reported, which may increase the risk for adverse events. If combination therapy is necessary, advise patients against driving or performing other hazardous activities until they know how the combination affects them.
    Isoflurane: (Major) Concomitant use of hydrocodone with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients receiving a general anesthetic. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Isoniazid, INH: (Major) Agents which induce the hepatic isoenzyme CYP2E1, such as isoniazid, may potentially increase the risk for acetaminophen-induced hepatotoxicity via generation of a greater percentage of acetaminophen's hepatotoxic metabolites. The combination of isoniazid and acetaminophen has caused severe hepatotoxicity in at least one patient; studies in rats have demonstrated that pre-treatment with isoniazid potentiates acetaminophen hepatotoxicity. (Moderate) Concomitant use of hydrocodone with isoniazid may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. Monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of isoniazid could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If isoniazid is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. isoniazid is a weak inhibitor of CYP3A4.
    Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Major) Agents which induce the hepatic isoenzyme CYP2E1, such as isoniazid, may potentially increase the risk for acetaminophen-induced hepatotoxicity via generation of a greater percentage of acetaminophen's hepatotoxic metabolites. The combination of isoniazid and acetaminophen has caused severe hepatotoxicity in at least one patient; studies in rats have demonstrated that pre-treatment with isoniazid potentiates acetaminophen hepatotoxicity. (Moderate) Agents which induce the hepatic isoenzymes CYP2E1 and CYP1A2, such as rifampin, may potentially increase the risk for acetaminophen-induced hepatotoxicity via generation of a greater percentage of acetaminophen's hepatotoxic metabolites. (Moderate) Concomitant use of hydrocodone with isoniazid may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. Monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of isoniazid could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If isoniazid is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. isoniazid is a weak inhibitor of CYP3A4. (Moderate) Concomitant use of hydrocodone with rifampin can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If rifampin is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and rifampin is a strong CYP3A4 inducer.
    Isoniazid, INH; Rifampin: (Major) Agents which induce the hepatic isoenzyme CYP2E1, such as isoniazid, may potentially increase the risk for acetaminophen-induced hepatotoxicity via generation of a greater percentage of acetaminophen's hepatotoxic metabolites. The combination of isoniazid and acetaminophen has caused severe hepatotoxicity in at least one patient; studies in rats have demonstrated that pre-treatment with isoniazid potentiates acetaminophen hepatotoxicity. (Moderate) Agents which induce the hepatic isoenzymes CYP2E1 and CYP1A2, such as rifampin, may potentially increase the risk for acetaminophen-induced hepatotoxicity via generation of a greater percentage of acetaminophen's hepatotoxic metabolites. (Moderate) Concomitant use of hydrocodone with isoniazid may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. Monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of isoniazid could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If isoniazid is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. isoniazid is a weak inhibitor of CYP3A4. (Moderate) Concomitant use of hydrocodone with rifampin can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal; consider increasing the dose of hydrocodone as needed. If rifampin is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and rifampin is a strong CYP3A4 inducer.
    Itraconazole: (Moderate) Concomitant use of hydrocodone with itraconazole may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of itraconazole could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If itraconazole is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Itraconazole is a strong inhibitor of CYP3A4.
    Ivacaftor: (Moderate) Concomitant use of hydrocodone with ivacaftor may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. Monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of ivacaftor could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If ivacaftor is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Ivacaftor is a weak inhibitor of CYP3A4.
    Ketamine: (Major) Concomitant use of hydrocodone with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Avoid prescribing opioid cough medications in patients receiving a general anesthetic. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Ketoconazole: (Moderate) Concomitant use of hydrocodone with ketoconazole may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of ketoconazole could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If ketoconazole is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Ketoconazole is a strong inhibitor of CYP3A4.
    Lactobacillus: (Moderate) Concurrent use of antidiarrheals and opiate agonists, can lead to severe constipation and possibly additive CNS depression. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
    Lactulose: (Minor) Concurrent use of hydrocodone with strong laxatives that rapidly increase gastrointestinal motility, such as lactulose, may decrease hydrocodone absorption. Closely monitor patients for changing analgesic requirements or adverse events.
    Lamivudine, 3TC; Zidovudine, ZDV: (Minor) Both acetaminophen and zidovudine, ZDV undergo glucuronidation. Competition for the metabolic pathway is thought to have caused a case of acetaminophen-related hepatotoxicity. This interaction may be more clinically significant in patients with depleted glutathione stores, such as patients with acquired immunodeficiency syndrome, poor nutrition, or alcoholism.
    Lamotrigine: (Major) Acetaminophen can be hepatotoxic, and lamotrigine appears to be a potential cause of progressive and fatal hepatotoxicity despite drug discontinuation. A 35 year-old developed fulminant liver failure possibly caused by lamotrigine. She was taking several other drugs including acetaminophen. In a randomized, single-dose study, the serum half-life of lamotrigine after a 300 mg dose decreased by 15% and the area under the plasma concentration-time curve decreased by 20% when given with acetaminophen 900 mg 3 times a day as compared with administration of lamotrigine with placebo. As the lamotrigine maximum serum concentration (Cmax) and time to Cmax was similar between the groups, and the lamotrigine renal clearance increased by 7%, acetaminophen appears to enhance removal of lamotrigine from the circulation.
    Lanthanum Carbonate: (Minor) The manufacturer recommends that oral compounds known to interact with antacids, such as acetaminophen, should not be taken within 2 hours of dosing with lanthanum carbonate.
    Lapatinib: (Moderate) Concomitant use of hydrocodone with lapatinib may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. Monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of lapatinib could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If lapatinib is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Lapatinib is a weak inhibitor of CYP3A4.
    Larotrectinib: (Moderate) Consider a reduced dose of hydrocodone with frequent monitoring for respiratory depression and sedation if concurrent use of larotrectinib is necessary. Hydrocodone is a CYP3A4 substrate, and coadministration with CYP3A4 inhibitors like larotrectinib can increase hydrocodone exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of hydrocodone. If larotrectinib is discontinued, hydrocodone plasma concentrations will decrease resulting in reduced efficacy of the opioid and potential withdrawal syndrome in a patient who has developed physical dependence to hydrocodone.
    Lesinurad: (Moderate) Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal if coadministration with lesinurad is necessary; consider increasing the dose of hydrocodone as needed. If lesinurad is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and lesinurad is a weak CYP3A4 inducer. Concomitant use with CYP3A4 inducers can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
    Lesinurad; Allopurinol: (Moderate) Monitor for reduced efficacy of hydrocodone and signs of opioid withdrawal if coadministration with lesinurad is necessary; consider increasing the dose of hydrocodone as needed. If lesinurad is discontinued, consider a dose reduction of hydrocodone and frequently monitor for signs or respiratory depression and sedation. Hydrocodone is a CYP3A4 substrate and lesinurad is a weak CYP3A4 inducer. Concomitant use with CYP3A4 inducers can decrease hydrocodone levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
    Letermovir: (Moderate) Concomitant use of hydrocodone with letermovir may increase hydrocodone plasma concentrations and prolong opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when hydrocodone is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of hydrocodone until stable drug effects are achieved. Discontinuation of letermovir could decrease hydrocodone plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to hydrocodone. If letermovir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Hydrocodone is a substrate for CYP3A4. Letermovir is a moderate inhibitor of CYP3A4; however, when given with cyclosporine, the combined effect on CYP3A4 substrates is similar to a strong CYP3A4 inhibitor.
    Levobupivacaine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics 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. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Levocetirizine: (Moderate) Concomitant use of opioid agonists with cetirizine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with cetirizine 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. Educate patients about the risks and symptoms of excessive CNS depression.
    Levomilnacipran: (Major) Because of the potential risk and severity of serotonin syndrome, caution and careful monitoring are recommended when administering serotonin norepinephrine reuptake inhibitors (SNRIs), such as levomilnacipran, with other drugs that have serotonergic properties such as hydrocodone. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Hydrocodone and levomilnacipran should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
    Levorphanol: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
    Lidocaine: (Moderate) Coadministration of lidocaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue lidocaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics 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. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
    Lincosamides: (Moderate) Lincosamides, which have been shown to exhibit neuromuscular blocking action, can enhance the effects of opiate agonists if used concomitantly, enhancing respiratory depressant effects. They should be used together with caution and the patient carefully monitored.
    Lixisenatide: (Minor) When 1,000 mg acetaminophen was given 1 or 4 hours after 10 mcg lixisenatide, the AUC was not significantly changed, but the acetaminophen Cmax was decreased by 29% and 31%, respectively and median Tmax was delayed by 2 and 1.75 hours, respectively. Acetaminophen AUC, Cmax, and Tmax were not significantly changed when acetaminophen was given 1 h before lixisenatide injection. The mechanism of this interaction is not available (although it may be due to delayed gastric emptying) and the clinical impact has not been assessed. To avoid potential pharmacokinetic interactions that might alter effectiveness of acetaminophen, it may be advisable for patients to take acetaminophen at least one hour prior to lixisenatide subcutaneous injection.
    Lofexidine: (Moderate) Monitor for excessive hypotension and sedation during coadministration of lofexidine and hydrocodone. Lofexidine can potentiate the effects of CNS depressants.
    Lomitapide: (Moderate) Caution should be exercised when lomitapide is used with other medications known to have potential for hepatotoxicity, such as acetaminophen (> 4 g/day PO for >= 3 days/week). The effect of concomitant administration of lomitapide with other hepatotoxic medications is unknown. More frequent monitoring of liver-related tests may be warranted.
    Loperamide: (Moderate) Additive constipation may be seen with concurrent use of opiate agonists and antidiarrheals. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal