Version July 2025
Hydrocodone/chlorpheniramine exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death. Reserve hydrocodone/chlorpheniramine for use in adult patients for whom the benefits of cough suppression are expected to outweigh the risks, and in whom an adequate assessment of the etiology of the cough has been made. Assess each patient's risk prior to prescribing hydrocodone/chlorpheniramine, prescribe hydrocodone/chlorpheniramine for the shortest duration that is consistent with individual patient treatment goals, monitor all patients regularly for the development of addiction or abuse, and refill only after reevaluation of the need for continued treatment.
Serious, life-threatening, or fatal respiratory depression may occur with use of hydrocodone/chlorpheniramine. Monitor for respiratory depression, especially during initiation of hydrocodone/chlorpheniramine therapy or when used in patients at higher risk.
Accidental ingestion of even one dose of hydrocodone/chlorpheniramine, especially by children, can result in a fatal overdose of hydrocodone.
Ensure accuracy when prescribing, dispensing, and administering hydrocodone/chlorpheniramine. Dosing errors can result in accidental overdose and death. Always use an accurate milliliter measuring device when measuring and administering hydrocodone/chlorpheniramine.
The concomitant use of hydrocodone/chlorpheniramine with all cytochrome P450 3A4 (CYP3A4) inhibitors may result in an increase in hydrocodone plasma concentrations, which could increase or prolong adverse drug effects and may cause potentially fatal respiratory depression. In addition, discontinuation of a concomitantly used CYP3A4 inducer may result in an increase in hydrocodone plasma concentration. Avoid the use of hydrocodone/chlorpheniramine in patients taking a CYP3A4 inhibitor or inducer.
Concomitant use of opioids with benzodiazepines or other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Avoid use of hydrocodone/chlorpheniramine in patients taking benzodiazepines, other CNS depressants, or alcohol.
Instruct patients not to consume alcoholic beverages or use prescription or nonprescription products that contain alcohol while taking hydrocodone/chlorpheniramine. The co-ingestion of alcohol with hydrocodone/chlorpheniramine may result in increased plasma levels and a potentially fatal overdose of hydrocodone.
Hydrocodone/chlorpheniramine is not recommended for use in pregnant women. Prolonged use of hydrocodone/chlorpheniramine during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life-threatening if not recognized and treated, and requires management according to protocols developed by neonatology experts. If hydrocodone/chlorpheniramine is used for a prolonged period in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available.
Cough and upper respiratory symptoms:
Extended release capsules (TussiCaps; hydrocodone 10 mg and chlorpheniramine 8 mg per capsule): Note: TussiCaps have been discontinued in the United States for more than 1 year.
Oral: 1 capsule every 12 hours; maximum: 2 capsules (hydrocodone 20 mg/chlorpheniramine 16 mg) per day.
Suspension (hydrocodone 10 mg and chlorpheniramine 8 mg per 5 mL): Oral: 5 mL every 12 hours; maximum: 10 mL (hydrocodone 20 mg/chlorpheniramine 16 mg) per day.
Discontinuation of therapy: When reducing the dose, discontinuing, or tapering long-term opioid therapy, the dose should be gradually tapered. An optimal tapering schedule has not been established. Individualize tapering based on discussions with patient to minimize withdrawal, while considering patient-specific goals and concerns and the opioid's pharmacokinetics. Proposed initial schedules range from slow (eg, 10% reduction per week or 10% reduction per month depending on duration of long-term therapy) to rapid (eg, 25% to 50% reduction every few days) (Ref). Slower tapers may be appropriate after long-term use (eg, >1 year), whereas more rapid tapers may be appropriate in patients experiencing severe adverse effects. During tapering, patients may be at an increased risk of overdose if they return to their original (or higher) opioid dose or use illicit opioids, due to rapid loss of tolerance; consider prescribing naloxone or nalmefene. Monitor carefully for signs/symptoms of withdrawal. If the patient displays withdrawal symptoms, consider slowing the taper schedule; alterations may include increasing the interval between dose reductions, decreasing amount of daily dose reduction, pausing the taper and restarting when the patient is ready, and/or coadministration of an alpha-2 agonist (eg, clonidine) to blunt autonomic withdrawal symptoms and other adjunctive agents to treat GI symptoms and muscle spasms, as needed. Continue to offer nonopioid analgesics as needed for pain management during the taper (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in the manufacturer's labeling; use with caution in severe renal impairment.
There are no dosage adjustments provided in the manufacturer's labeling; use with caution in severe hepatic impairment.
Avoid use (Ref).
(For additional information see "Hydrocodone and chlorpheniramine: Pediatric drug information")
Dosage guidance:
Safety: Due to risk of adverse effects (slowed or difficult breathing, misuse, abuse, substance use disorder, overdose, and death), the FDA in January 2018 recommended against routine use of codeine/hydrocodone-containing cough/cold products for patients <18 years and that future manufacturer labeling for these products include a contraindication in this population (Ref). TussiCaps have been discontinued in the United States for more than 1 year.
Cough (antitussive/antihistamine): Note: Oral liquid products (immediate-release solution and extended-release suspension) are NOT indicated for patients <18 years.
Extended-release capsules: Oral:
Children 6 to <12 years: Half-strength capsule (Hydrocodone 5 mg and chlorpheniramine 4 mg per capsule): One half-strength capsule every 12 hours; maximum daily dose: 2 capsules/24 hours.
Children ≥12 years and Adolescents: Full-strength capsule (Hydrocodone 10 mg and chlorpheniramine 8 mg per capsule): One full-strength capsule every 12 hours; maximum daily dose: 2 capsules/24 hours.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in the manufacturer's labeling; use with caution.
There are no dosage adjustments provided in the manufacturer's labeling; use with caution.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Also refer to Chlorpheniramine monograph. Frequency not defined.
Cardiovascular: Chest tightness
Central nervous system: Agitation, anxiety, confusion, decreased mental acuity, dizziness, drowsiness, drug dependence, dysphoria, euphoria, fear, headache, irritability, lethargy, mood changes, sedation
Dermatologic: Diaphoresis, erythema, pruritus, skin rash, urticaria
Gastrointestinal: Abdominal distention, abdominal pain, acute pancreatitis, constipation, decreased appetite, dyspepsia, epigastric distress, nausea, vomiting, xerostomia
Genitourinary: Dysuria, ureteral spasm, urinary frequency, urinary hesitancy, urinary retention
Neuromuscular & skeletal: Facial dyskinesia, tremor, vesicle sphincter spasm
Ophthalmic: Blurred vision, diplopia, visual disturbance
Respiratory: Dry throat, dyspnea, laryngismus, respiratory depression, wheezing
Postmarketing and/or case reports: Allodynia (opioid-induced hyperalgesia) (FDA Safety Communication 2023), hypogonadism (Brennan 2013; Debono 2011)
Hypersensitivity to hydrocodone, chlorpheniramine, or any component of the formulation; pediatric patients <6 years of age.
ER suspension: Additional contraindications: Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment; GI obstruction, including paralytic ileus (known or suspected); significant respiratory depression.
Concerns related to adverse effects:
• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery, driving).
• Hypotension: May cause severe hypotension (including orthostatic hypotension and syncope); use with caution in patients with hypovolemia, cardiovascular disease (including acute MI), or drugs that may exaggerate hypotensive effects (including phenothiazines or general anesthetics). Monitor for symptoms of hypotension following initiation or dose titration. Avoid use in patients with circulatory shock.
• Phenanthrene hypersensitivity: Use with caution in patients with hypersensitivity reactions to other phenanthrene-derivative opioid agonists (codeine, hydromorphone, levorphanol, morphine, oxycodone, oxymorphone).
• Respiratory depression: Fatal respiratory depression may occur. Carbon dioxide retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids. Patients and caregivers should be educated on how to recognize respiratory depression and the importance of getting emergency assistance immediately (eg, calling 911) in the event of known or suspected overdose.
Disease-related concerns:
• Abdominal conditions: May obscure diagnosis or clinical course of patients with acute abdominal conditions.
• Adrenocortical insufficiency: Use with caution in patients with adrenal insufficiency, including Addison disease. Long-term opioid use may cause secondary hypogonadism, which may lead to mood disorders and osteoporosis (Brennan 2013).
• Biliary tract impairment: Use with caution in patients with biliary tract dysfunction or acute pancreatitis; opioids may cause constriction of sphincter of Oddi.
• CNS depression/coma: Avoid use in patients with impaired consciousness or coma as these patients are susceptible to intracranial effects of CO2 retention.
• Delirium tremens: Use with caution in patients with delirium tremens.
• Head trauma: Avoid use in patients with head injury, intracranial lesions, or elevated intracranial pressure (ICP); exaggerated elevation of ICP may occur.
• Hepatic impairment: Use with caution in patients with severe hepatic impairment.
• Increased intraocular pressure/glaucoma: Use with caution in patients with increased intraocular pressure or glaucoma.
• Obesity: Use with caution in patients who are morbidly obese.
• Obstructive bowel disease: Use with caution in patients with obstructive bowel disease.
• Prostatic hyperplasia/urinary obstruction: Use with caution in patients with prostatic hyperplasia and/or urinary stricture.
• Psychosis: Use with caution in patients with toxic psychosis.
• Renal impairment: Use with caution in patients with severe renal impairment.
• Respiratory disease: Patients with significant chronic obstructive pulmonary disease or cor pulmonale, and those having a substantially decreased respiratory reserve, hypoxia, hypercarbia, or preexisting respiratory depression are at increased risk of critical respiratory depression even at therapeutic doses; monitor for respiratory depression, particularly when initiating therapy. Consider the use of alternative nonopioid analgesics in these patients. Avoid use in patients with compromised respiratory function, patients at risk of respiratory failure, patients with productive cough accompanied by fever, and patients with chronic respiratory disease. Use is contraindicated in patients with acute or severe bronchial asthma in an unmonitored setting or without resuscitative equipment.
• Seizures: Use with caution in patients with a history of seizure disorder; may cause or exacerbate preexisting seizures.
• Sleep-related disorders: Use with caution in patients with sleep-related disorders, including sleep apnea, due to increased risk for respiratory and central nervous system depression. Monitor carefully and titrate dosage cautiously in patients with mild sleep-disordered breathing. Avoid opioids in patients with moderate to severe sleep-disordered breathing (CDC [Dowell 2022]).
• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction.
Concurrent drug therapy issues:
• Benzodiazepines or other CNS depressants: Concomitant use may result in respiratory depression and sedation, which may be fatal. Consider prescribing naloxone or nalmefene for emergency treatment of opioid overdose in patients taking benzodiazepines or other CNS depressants concomitantly with opioids.
• Ethanol use: Do not consume alcoholic beverages or use prescription or nonprescription products that contain alcohol while taking hydrocodone/chlorpheniramine. Coingestion of alcohol may result in increased plasma levels and a potentially fatal overdose of hydrocodone.
Special populations:
• CYP2D6 poor or intermediate metabolizers: Due to the role of CYP2D6 in the metabolism of hydrocodone to hydromorphone (an active metabolite with higher binding affinity to mu-opioid receptors compared to hydrocodone), CYP2D6 poor and intermediate metabolizers may have decreased hydromorphone formation. However, limited data exist to determine if clinically significant differences of analgesia and toxicity can be predicted based on CYP2D6 phenotype (CPIC [Crews 2021]).
• Cachectic or debilitated patients: Avoid use in cachectic or debilitated patients; there is a greater potential for critical respiratory depression, even at therapeutic dosages.
• Neonates: Neonatal withdrawal syndrome: Signs and symptoms include irritability, hyperactivity and abnormal sleep pattern, high-pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. Onset, duration, and severity depend on the drug used, duration of use, maternal dose, and rate of drug elimination by the newborn.
• Older adult: Use opioids with caution in older adults; may be more sensitive to adverse effects. Clearance may also be reduced in older adults (with or without renal impairment) resulting in a narrow therapeutic window and increased adverse effects. Monitor closely for adverse effects associated with opioid therapy (eg, respiratory and central nervous system depression, falls, cognitive impairment, constipation) (CDC [Dowell 2022]).
• Pediatric: Respiratory depression may occur even at therapeutic dosages; FDA and AAP recommend against use in pediatric patients <18 years due to risk of adverse effects.
Dosage form specific issues:
• Polysorbate 80: Some dosage forms may contain polysorbate 80 (also known as Tweens). Hypersensitivity reactions, usually a delayed reaction, have been reported following exposure to pharmaceutical products containing polysorbate 80 in certain individuals (Isaksson 2002; Lucente 2000; Shelley 1995). Thrombocytopenia, ascites, pulmonary deterioration, and renal and hepatic failure have been reported in premature neonates after receiving parenteral products containing polysorbate 80 (Alade 1986; CDC 1984). See manufacturer's labeling.
• Propylene glycol: Some dosage forms may contain propylene glycol; large amounts are potentially toxic and have been associated hyperosmolality, lactic acidosis, seizures and respiratory depression; use caution (AAP 1997; Zar 2007).
Other warnings/precautions:
• Abuse/misuse/diversion: Use exposes patients and other users to the risks of substance use disorder, abuse, and misuse, potentially leading to overdose and death. Reserve for use in adults for whom the benefits of cough suppression are expected to outweigh the risks, and in whom an adequate assessment of the etiology of the cough has been made. Assess each patient's risk prior to prescribing; prescribe for the shortest duration that is consistent with individual patient treatment goals; monitor all patients regularly for development of these behaviors or conditions; and refill only after reevaluation of the need for continued treatment. Use with caution in patients with a history of substance abuse disorder; potential for drug dependency exists. Other factors associated with increased risk for misuse include concomitant depression or other mental health conditions, higher opioid dosages, or taking other central nervous system depressants. Consider offering naloxone or nalmefene prescriptions in patients with an increased risk for overdose, such as history of overdose or substance use disorder, higher opioid dosages (≥50 morphine milligram equivalents [MME]/day orally), concomitant benzodiazepine use, and patients at risk for returning to a high dose after losing tolerance (CDC [Dowell 2022]).
• Cough: Appropriate use: Underlying cause of cough should be determined prior to prescribing. Dosage should not be increased if cough fails to respond; an unresponsive cough should be reevaluated in 5 days or sooner for possible underlying pathology.
• Frequency of dosing: Appropriate use: Capsules and suspension should not be given any more frequently than every 12 hours.
• Naloxone/nalmefene access: Discuss the availability of naloxone or nalmefene with all patients who are prescribed opioid analgesics, as well as their caregivers, and consider prescribing it to patients who are at increased risk of opioid overdose. These include patients who are also taking benzodiazepines or other CNS depressants, have an opioid use disorder (OUD) (current or history of), or have experienced opioid-induced respiratory depression/opioid overdose. Additionally, health care providers should consider prescribing naloxone or nalmefene to patients prescribed medications to treat OUD; patients at risk of opioid overdose even if they are not taking an opioid analgesic or medication to treat OUD; and patients taking opioids, including methadone or buprenorphine for OUD, if they have household members, including children, or other close contacts at risk for accidental ingestion or opioid overdose. Inform patients and caregivers on options for obtaining naloxone or nalmefene (eg, by prescription, directly from a pharmacist, a community-based program) as permitted by state dispensing and prescribing guidelines. Educate patients and caregivers on how to recognize respiratory depression, proper administration of naloxone or nalmefene, and getting emergency help (FDA 2020).
In January 2018, the FDA expanded the earlier warnings about codeine-containing cough/cold products to include hydrocodone-containing products. The FDA is recommending that labeling for hydrocodone-containing cough and cold products include a contraindication for use in pediatric patients <18 years of age due to risk of adverse events, including slowed or difficult breathing, misuse, abuse, substance use disorder, overdose, and death. Additionally, the FDA will be requiring a black box warning on all prescription cough/cold products that contain codeine or hydrocodone to include the warnings (AAP 2018; FDA 2018a; FDA 2018b).
Safety and efficacy for the use of cough and cold products in pediatric patients <4 years of age is limited; the AAP warns against the use of these products for respiratory illnesses in young children. Serious adverse effects including death have been reported. Many of these products contain multiple active ingredients, increasing the risk of accidental overdose when used with other products. Health care providers are reminded to ask caregivers about the use of OTC cough and cold products in order to avoid exposure to multiple medications containing the same ingredient (AAP 2018; CDC 2007; FDA 2017; FDA 2018c).
Some dosage forms may contain propylene glycol; in neonates large amounts of propylene glycol delivered orally, intravenously (eg, >3,000 mg/day), or topically have been associated with potentially fatal toxicities which can include metabolic acidosis, seizures, renal failure, and CNS depression; toxicities have also been reported in children and adults including hyperosmolality, lactic acidosis, seizures and respiratory depression; use caution (AAP 1997; Shehab 2009).
TussiCaps have been discontinued in the United States for more than 1 year.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Capsule Extended Release 12 Hour, Oral:
TussiCaps: Hydrocodone polistirex [equivalent to hydrocodone bitartrate 10 mg] and chlorpheniramine polistirex [equivalent to chlorpheniramine maleate 8 mg] [DSC] [contains fd&c blue #1 (brill blue) aluminum lake, fd&c blue #2 (indigo carm) aluminum lake, fd&c red #40(allura red ac)aluminum lake, quinoline (d&c yellow #10) aluminum lake, quinoline yellow (d&c yellow #10)]
Suspension Extended Release, Oral:
Generic: Hydrocodone polistirex [equivalent to hydrocodone bitartrate 10 mg] and chlorpheniramine polistirex [equivalent to chlorpheniramine maleate 8 mg] per 5 mL (70 mL [DSC], 115 mL, 118 mL [DSC], 473 mL)
May be product dependent
Suspension Extended Release (Hydrocod Poli-Chlorphe Poli ER Oral)
10-8 mg/5 mL (per mL): $0.67
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C-II
Oral:
Capsule: Administer without regard to meals. Do not dilute with fluid or mix with other medications.
Suspension: Use an accurate measuring device; a household teaspoon is not an accurate measuring device. Administer without regard to meals. Shake well before administering dose; do not dilute with other fluids or mix with other medications.
Bariatric surgery: Capsule, extended release: Some institutions may have specific protocols that conflict with these recommendations; refer to institutional protocols as appropriate. Do not cut, crush, or chew. Switch to oral suspension.
Oral: Extended release: Capsules: Administer without regard to meals. Swallow whole. Do not dilute with fluid or mix with other medications as this may affect absorption rate.
An FDA-approved patient medication guide, which is available with the product information and as follows, must be dispensed with this medication:
Tussionex Pennkinetic ER: https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/019111s022lbl.pdf#page=25
Cough and upper respiratory tract symptoms: Temporary relief of cough and upper respiratory tract symptoms associated with allergy or the common cold.
Limitations of use: Reserve for use in patients for whom the benefits of cough suppression are expected to outweigh the risks, and in whom an adequate assessment of the etiology of the cough has been made.
Tussionex represents a different product in the US than it does in Canada. In the US, Tussionex (Pennkinetic) contains hydrocodone and chlorpheniramine, while in Canada the product bearing this name contains hydrocodone and phenyltoloxamine.
The Institute for Safe Medication Practices (ISMP) includes this medication among its list of drug classes (opioids, all formulations and routes of administration; pediatric liquid medications requiring measurement) which have a heightened risk of causing significant patient harm when used in error (High-Alert Medications in Acute Care, Community/Ambulatory Care, and Long-Term Care Settings).
Beers Criteria: Chlorpheniramine, a first-generation antihistamine, is identified in the Beers Criteria as a potentially inappropriate medication to be avoided in patients 65 years and older (independent of diagnosis or condition) due to its potent anticholinergic properties resulting in increased risk of confusion, dry mouth, constipation, and other anticholinergic effects or toxicity; use should also be avoided due to reduced clearance with advanced age and tolerance associated with use as a hypnotic. Exposure to concurrent anticholinergic drugs also increases risk of falls, delirium, and dementia; consider total anticholinergic burden when conducting medication reviews (Beers Criteria [AGS 2023]).
Refer to individual components.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Acetylcholinesterase Inhibitors: May decrease therapeutic effects of Agents with Clinically Relevant Anticholinergic Effects. Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Acetylcholinesterase Inhibitors. Risk C: Monitor
Aclidinium: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Ajmaline: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Alcohol (Ethyl): May increase CNS depressant effects of HYDROcodone. Alcohol (Ethyl) may increase serum concentration of HYDROcodone. Management: Patients using hydrocodone extended-release capsules must not consume alcohol or alcohol-containing products due to possibly fatal outcomes. Other hydrocodone products are also expected to interact, but to a less significant degree. Risk X: Avoid
Alizapride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Alvimopan: Opioid Agonists may increase adverse/toxic effects of Alvimopan. This is most notable for patients receiving long-term (i.e., more than 7 days) opiates prior to alvimopan initiation. Management: Alvimopan is contraindicated in patients receiving therapeutic doses of opioids for more than 7 consecutive days immediately prior to alvimopan initiation. Risk D: Consider Therapy Modification
Amantadine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Amezinium: Antihistamines may increase stimulatory effects of Amezinium. Risk C: Monitor
Amisulpride (Oral): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Amphetamines: May increase analgesic effects of Opioid Agonists. Risk C: Monitor
Artemether and Lumefantrine: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Articaine: May increase CNS depressant effects of CNS Depressants. Management: Consider reducing the dose of articaine if possible when used in patients who are also receiving CNS depressants. Monitor for excessive CNS depressant effects with any combined use. Risk D: Consider Therapy Modification
Azelastine (Nasal): May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Benperidol: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Benperidol. Risk C: Monitor
Benperidol: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Benztropine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Benztropine. Risk C: Monitor
Benzylpenicilloyl Polylysine: Coadministration of Antihistamines and Benzylpenicilloyl Polylysine may alter diagnostic results. Management: Suspend systemic H1 antagonists for benzylpenicilloyl-polylysine skin testing and delay testing until systemic antihistaminic effects have dissipated. A histamine skin test may be used to assess persistent antihistaminic effects. Risk D: Consider Therapy Modification
Betahistine: Antihistamines may decrease therapeutic effects of Betahistine. Betahistine may decrease therapeutic effects of Antihistamines. Risk C: Monitor
Biperiden: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Biperiden. Risk C: Monitor
Blonanserin: CNS Depressants may increase CNS depressant effects of Blonanserin. Management: Use caution if coadministering blonanserin and CNS depressants; dose reduction of the other CNS depressant may be required. Strong CNS depressants should not be coadministered with blonanserin. Risk D: Consider Therapy Modification
Bornaprine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Bornaprine. Risk C: Monitor
Botulinum Toxin-Containing Products: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Brimonidine (Topical): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Bromopride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Bromperidol: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Buclizine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Buclizine. Risk C: Monitor
Buclizine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Buprenorphine: CNS Depressants may increase CNS depressant effects of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine at lower doses in patients already receiving CNS depressants. Risk D: Consider Therapy Modification
Buprenorphine: May decrease therapeutic effects of Opioid Agonists. Management: Seek alternatives to buprenorphine in patients receiving pure opioid agonists. If combined in certain pain management situations (eg, surgery), monitor for symptoms of therapeutic failure/high dose requirements or opioid withdrawal symptoms. Risk D: Consider Therapy Modification
BusPIRone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Cannabinoid-Containing Products: Agents with Clinically Relevant Anticholinergic Effects may increase tachycardic effects of Cannabinoid-Containing Products. Risk C: Monitor
Cannabinoid-Containing Products: CNS Depressants may increase CNS depressant effects of Cannabinoid-Containing Products. Risk C: Monitor
Certoparin: Antihistamines may increase therapeutic effects of Certoparin. Risk C: Monitor
Cetirizine (Systemic): May increase CNS depressant effects of CNS Depressants. Management: Consider avoiding this combination if possible. If required, monitor for excessive sedation or CNS depression, limit the dose and duration of combination therapy, and consider CNS depressant dose reductions. Risk D: Consider Therapy Modification
Chloral Hydrate/Chloral Betaine: CNS Depressants may increase CNS depressant effects of Chloral Hydrate/Chloral Betaine. Management: Consider alternatives to the use of chloral hydrate or chloral betaine and additional CNS depressants. If combined, consider a dose reduction of either agent and monitor closely for enhanced CNS depressive effects. Risk D: Consider Therapy Modification
Chlormethiazole: May increase CNS depressant effects of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Risk D: Consider Therapy Modification
Chlorphenesin Carbamate: May increase adverse/toxic effects of CNS Depressants. Risk C: Monitor
Cimetropium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Cimetropium. Risk X: Avoid
Clofazimine: May increase serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Risk C: Monitor
CloZAPine: Agents with Clinically Relevant Anticholinergic Effects may increase constipating effects of CloZAPine. Management: Consider alternatives to this combination whenever possible. If combined, monitor closely for signs and symptoms of gastrointestinal hypomotility and consider prophylactic laxative treatment. Risk D: Consider Therapy Modification
CYP2D6 Inhibitors (Strong): May decrease active metabolite exposure of HYDROcodone. Specifically, concentrations of hydromorphone may be decreased. Risk C: Monitor
CYP2D6 Inhibitors (Strong): May increase serum concentration of Chlorpheniramine. Risk C: Monitor
CYP3A4 Inducers (Moderate): May decrease serum concentration of HYDROcodone. Risk C: Monitor
CYP3A4 Inducers (Strong): May decrease serum concentration of HYDROcodone. Risk C: Monitor
CYP3A4 Inhibitors (Moderate): May increase serum concentration of HYDROcodone. Risk C: Monitor
CYP3A4 Inhibitors (Strong): May increase serum concentration of HYDROcodone. Risk C: Monitor
Daridorexant: May increase CNS depressant effects of CNS Depressants. Management: Dose reduction of daridorexant and/or any other CNS depressant may be necessary. Use of daridorexant with alcohol is not recommended, and the use of daridorexant with any other drug to treat insomnia is not recommended. Risk D: Consider Therapy Modification
Darifenacin: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Darifenacin. Risk C: Monitor
Desmopressin: Opioid Agonists may increase hyponatremic effects of Desmopressin. Risk C: Monitor
DexmedeTOMIDine: CNS Depressants may increase CNS depressant effects of DexmedeTOMIDine. Management: Monitor for increased CNS depression during coadministration of dexmedetomidine and CNS depressants, and consider dose reductions of either agent to avoid excessive CNS depression. Risk D: Consider Therapy Modification
Dicyclomine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Dicyclomine. Risk C: Monitor
Difelikefalin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Dihydralazine: CNS Depressants may increase hypotensive effects of Dihydralazine. Risk C: Monitor
Dimethindene (Topical): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Diuretics: Opioid Agonists may increase adverse/toxic effects of Diuretics. Opioid Agonists may decrease therapeutic effects of Diuretics. Risk C: Monitor
Dothiepin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
DroNABinol: Agents with Clinically Relevant Anticholinergic Effects may increase tachycardic effects of DroNABinol. Risk X: Avoid
DroPERidol: May increase CNS depressant effects of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Risk D: Consider Therapy Modification
Eluxadoline: Agents with Clinically Relevant Anticholinergic Effects may increase constipating effects of Eluxadoline. Risk X: Avoid
Eluxadoline: Opioid Agonists may increase constipating effects of Eluxadoline. Risk X: Avoid
Emedastine (Systemic): May increase CNS depressant effects of CNS Depressants. Management: Consider avoiding this combination if possible. If required, monitor for excessive sedation or CNS depression, limit the dose and duration of combination therapy, and consider CNS depressant dose reductions. Risk C: Monitor
Entacapone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Fesoterodine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Fesoterodine. Risk C: Monitor
Flunarizine: CNS Depressants may increase CNS depressant effects of Flunarizine. Risk X: Avoid
Flunitrazepam: CNS Depressants may increase CNS depressant effects of Flunitrazepam. Management: Reduce the dose of CNS depressants when combined with flunitrazepam and monitor patients for evidence of CNS depression (eg, sedation, respiratory depression). Use non-CNS depressant alternatives when available. Risk D: Consider Therapy Modification
Fosphenytoin-Phenytoin: Chlorpheniramine may increase serum concentration of Fosphenytoin-Phenytoin. Risk C: Monitor
Fusidic Acid (Systemic): May increase serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Management: Consider avoiding this combination if possible. If required, monitor patients closely for increased adverse effects of the CYP3A4 substrate. Risk D: Consider Therapy Modification
Gastrointestinal Agents (Prokinetic): Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Gastrointestinal Agents (Prokinetic). Risk C: Monitor
Gastrointestinal Agents (Prokinetic): Opioid Agonists may decrease therapeutic effects of Gastrointestinal Agents (Prokinetic). Risk C: Monitor
Gepotidacin: May decrease anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Glucagon: Agents with Clinically Relevant Anticholinergic Effects may increase adverse/toxic effects of Glucagon. Specifically, the risk of gastrointestinal adverse effects may be increased. Risk C: Monitor
Glycopyrrolate (Oral Inhalation): Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Glycopyrrolate (Oral Inhalation). Risk X: Avoid
Glycopyrrolate (Systemic): Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Glycopyrrolate (Systemic). Risk C: Monitor
Glycopyrronium (Topical): May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Grapefruit Juice: May increase serum concentration of HYDROcodone. Risk C: Monitor
Hyaluronidase: Antihistamines may decrease therapeutic effects of Hyaluronidase. Risk C: Monitor
HydrOXYzine: May increase CNS depressant effects of CNS Depressants. Management: Consider a decrease in the CNS depressant dose, as appropriate, when used together with hydroxyzine. Increase monitoring of signs/symptoms of CNS depression in any patient receiving hydroxyzine together with another CNS depressant. Risk D: Consider Therapy Modification
Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies): May decrease therapeutic effects of Opioid Agonists. Opioid Agonists may decrease therapeutic effects of Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies). Risk C: Monitor
Ipratropium (Nasal): May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Ipratropium (Oral Inhalation): May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Isoproterenol: Chlorpheniramine may increase therapeutic effects of Isoproterenol. Risk C: Monitor
Itopride: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Itopride. Risk C: Monitor
Ixabepilone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Kava Kava: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Ketotifen (Systemic): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Kratom: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Lemborexant: May increase CNS depressant effects of CNS Depressants. Management: Dosage adjustments of lemborexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive CNS depressant effects. Close monitoring for CNS depressant effects is necessary. Risk D: Consider Therapy Modification
Levocetirizine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Levosulpiride: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Levosulpiride. Risk X: Avoid
Lisuride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Lofexidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Loxapine: CNS Depressants may increase CNS depressant effects of Loxapine. Management: Consider reducing the dose of CNS depressants administered concomitantly with loxapine due to an increased risk of respiratory depression, sedation, hypotension, and syncope. Risk D: Consider Therapy Modification
Magnesium Sulfate: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Mavorixafor: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk X: Avoid
Melperone: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Mequitazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Metergoline: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Methotrimeprazine: CNS Depressants may increase CNS depressant effects of Methotrimeprazine. Methotrimeprazine may increase CNS depressant effects of CNS Depressants. Management: Reduce the usual dose of CNS depressants by 50% if starting methotrimeprazine until the dose of methotrimeprazine is stable. Monitor patient closely for evidence of CNS depression. Risk D: Consider Therapy Modification
Methscopolamine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Methscopolamine. Risk C: Monitor
Metoclopramide: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
MetyroSINE: CNS Depressants may increase sedative effects of MetyroSINE. Risk C: Monitor
Minocycline (Systemic): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Mirabegron: Agents with Clinically Relevant Anticholinergic Effects may increase adverse/toxic effects of Mirabegron. Risk C: Monitor
Monoamine Oxidase Inhibitors: HYDROcodone may increase serotonergic effects of Monoamine Oxidase Inhibitors. This could result in serotonin syndrome. Monoamine Oxidase Inhibitors may increase adverse/toxic effects of HYDROcodone. Management: Consider alternatives to this combination when possible. If coadministration is required, use test doses, titrate small doses frequently, and monitor patients closely for evidence of serotonergic and opioid toxicities. Risk D: Consider Therapy Modification
Moxonidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Nabilone: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Nalfurafine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Nalfurafine: Opioid Agonists may increase adverse/toxic effects of Nalfurafine. Opioid Agonists may decrease therapeutic effects of Nalfurafine. Risk C: Monitor
Nalmefene: May decrease therapeutic effects of Opioid Agonists. Management: Avoid the concomitant use of oral nalmefene and opioid agonists. Discontinue oral nalmefene 1 week prior to any anticipated use of opioid agonists. If combined, larger doses of opioid agonists will likely be required. Risk D: Consider Therapy Modification
Naltrexone: May decrease therapeutic effects of Opioid Agonists. Management: Seek therapeutic alternatives to opioids. See full drug interaction monograph for detailed recommendations. Risk X: Avoid
Nefazodone: Opioid Agonists (metabolized by CYP3A4 and CYP2D6) may increase serotonergic effects of Nefazodone. This could result in serotonin syndrome. Nefazodone may increase serum concentration of Opioid Agonists (metabolized by CYP3A4 and CYP2D6). Management: Monitor for increased opioid effects, including fatal respiratory depression, when these agents are combined and consider opioid dose reductions until stable drug effects are achieved. Additionally, monitor for serotonin syndrome/serotonin toxicity. Risk C: Monitor
Nitroglycerin: Agents with Clinically Relevant Anticholinergic Effects may decrease absorption of Nitroglycerin. Specifically, anticholinergic agents may decrease the dissolution of sublingual nitroglycerin tablets, possibly impairing or slowing nitroglycerin absorption. Risk C: Monitor
Noscapine: CNS Depressants may increase adverse/toxic effects of Noscapine. Risk X: Avoid
Olopatadine (Nasal): May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Ombitasvir, Paritaprevir, and Ritonavir: May increase serum concentration of HYDROcodone. Management: Reduce the hydrocodone dose by 50% during concurrent use of ombitasvir, paritaprevir, and ritonavir; monitor closely for both analgesic effectiveness and for signs of toxicity or withdrawal. Risk D: Consider Therapy Modification
Ombitasvir, Paritaprevir, Ritonavir, and Dasabuvir: May increase serum concentration of HYDROcodone. Management: Reduce the hydrocodone dose by 50% during concurrent use of ombitasvir, paritaprevir, ritonavir, and dasabuvir; monitor closely for both analgesic effectiveness and for signs of toxicity or withdrawal. Risk D: Consider Therapy Modification
Opicapone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Opioids (Mixed Agonist / Antagonist): May decrease analgesic effects of Opioid Agonists. Management: Seek alternatives to mixed agonist/antagonist opioids in patients receiving pure opioid agonists, and monitor for symptoms of therapeutic failure/high dose requirements (or withdrawal in opioid-dependent patients) if patients receive these combinations. Risk X: Avoid
Opipramol: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Opipramol: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Orphenadrine: CNS Depressants may increase CNS depressant effects of Orphenadrine. Risk X: Avoid
Oxatomide: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Oxomemazine: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Oxybate Salt Products: CNS Depressants may increase CNS depressant effects of Oxybate Salt Products. Management: Consider alternatives to this combination when possible. If combined, dose reduction or discontinuation of one or more CNS depressants (including the oxybate salt product) should be considered. Interrupt oxybate salt treatment during short-term opioid use Risk D: Consider Therapy Modification
OxyBUTYnin: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of OxyBUTYnin. Risk C: Monitor
OxyCODONE: CNS Depressants may increase CNS depressant effects of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Risk D: Consider Therapy Modification
Paraldehyde: CNS Depressants may increase CNS depressant effects of Paraldehyde. Risk X: Avoid
Peginterferon Alfa-2b: May decrease serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Peginterferon Alfa-2b may increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Pegvisomant: Opioid Agonists may decrease therapeutic effects of Pegvisomant. Risk C: Monitor
Perazine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Periciazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Perphenazine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Perphenazine. Risk C: Monitor
PHENobarbital: May increase CNS depressant effects of HYDROcodone. PHENobarbital may decrease serum concentration of HYDROcodone. Management: Avoid use of hydrocodone and phenobarbital when possible. Monitor for respiratory depression/sedation. Because phenobarbital is also a moderate CYP3A4 inducer, monitor for decreased hydrocodone efficacy and withdrawal if combined. Risk D: Consider Therapy Modification
Pipamperone: May increase adverse/toxic effects of CNS Depressants. Risk C: Monitor
Piribedil: CNS Depressants may increase CNS depressant effects of Piribedil. Risk C: Monitor
Pitolisant: Antihistamines may decrease therapeutic effects of Pitolisant. Risk X: Avoid
Potassium Chloride: Agents with Clinically Relevant Anticholinergic Effects may increase ulcerogenic effects of Potassium Chloride. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium chloride. Risk X: Avoid
Potassium Citrate: Agents with Clinically Relevant Anticholinergic Effects may increase ulcerogenic effects of Potassium Citrate. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium citrate. Risk X: Avoid
Pramipexole: CNS Depressants may increase sedative effects of Pramipexole. Risk C: Monitor
Pramlintide: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. These effects are specific to the GI tract. Risk X: Avoid
Primidone: May increase CNS depressant effects of HYDROcodone. Primidone may decrease serum concentration of HYDROcodone. Management: Avoid use of hydrocodone and primidone when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased hydrocodone efficacy and withdrawal if combined. Risk D: Consider Therapy Modification
Procarbazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Propantheline: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Propantheline. Risk C: Monitor
Propiverine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
QT-prolonging Agents (Highest Risk): QT-prolonging Agents (Indeterminate Risk - Caution) may increase QTc-prolonging effects of QT-prolonging Agents (Highest Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
QuiNIDine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Ramosetron: Agents with Clinically Relevant Anticholinergic Effects may increase constipating effects of Ramosetron. Risk C: Monitor
Ramosetron: Opioid Agonists may increase constipating effects of Ramosetron. Risk C: Monitor
Revefenacin: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Revefenacin. Risk X: Avoid
Rilmenidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Rivastigmine: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Rivastigmine. Rivastigmine may decrease therapeutic effects of Agents with Clinically Relevant Anticholinergic Effects. Management: Use of rivastigmine with an anticholinergic agent is not recommended unless clinically necessary. If the combination is necessary, monitor for reduced anticholinergic effects. Risk D: Consider Therapy Modification
Ropeginterferon Alfa-2b: CNS Depressants may increase adverse/toxic effects of Ropeginterferon Alfa-2b. Specifically, the risk of neuropsychiatric adverse effects may be increased. Management: Avoid coadministration of ropeginterferon alfa-2b and other CNS depressants. If this combination cannot be avoided, monitor patients for neuropsychiatric adverse effects (eg, depression, suicidal ideation, aggression, mania). Risk D: Consider Therapy Modification
ROPINIRole: CNS Depressants may increase sedative effects of ROPINIRole. Risk C: Monitor
Rotigotine: CNS Depressants may increase sedative effects of Rotigotine. Risk C: Monitor
Samidorphan: May decrease therapeutic effects of Opioid Agonists. Risk X: Avoid
Secretin: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Secretin. Management: Avoid concomitant use of anticholinergic agents and secretin. Discontinue anticholinergic agents at least 5 half-lives prior to administration of secretin. Risk D: Consider Therapy Modification
Serotonergic Agents (High Risk): Opioid Agonists (metabolized by CYP3A4 and CYP2D6) may increase serotonergic effects of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Risk C: Monitor
Sincalide: Drugs that Affect Gallbladder Function may decrease therapeutic effects of Sincalide. Management: Consider discontinuing drugs that may affect gallbladder motility prior to the use of sincalide to stimulate gallbladder contraction. Risk D: Consider Therapy Modification
Sofpironium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Sofpironium. Risk X: Avoid
Somatostatin Analogs: Opioid Agonists may decrease analgesic effects of Somatostatin Analogs. Opioid Agonists may increase analgesic effects of Somatostatin Analogs. Risk C: Monitor
Succinylcholine: May increase bradycardic effects of Opioid Agonists. Risk C: Monitor
Suvorexant: CNS Depressants may increase CNS depressant effects of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Risk D: Consider Therapy Modification
Thalidomide: CNS Depressants may increase CNS depressant effects of Thalidomide. Risk X: Avoid
Thiazide and Thiazide-Like Diuretics: Agents with Clinically Relevant Anticholinergic Effects may increase serum concentration of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Tiapride: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Tiapride. Risk C: Monitor
Tilidine: May increase therapeutic effects of Opioid Agonists. Risk X: Avoid
Tiotropium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Tiotropium. Risk X: Avoid
Tolterodine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Tolterodine. Risk C: Monitor
Tranylcypromine: May increase anticholinergic effects of Antihistamines, First Generation. Risk X: Avoid
Trospium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Trospium. Risk C: Monitor
Umeclidinium: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Valerian: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Zolpidem: CNS Depressants may increase CNS depressant effects of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Risk D: Consider Therapy Modification
Zuranolone: May increase CNS depressant effects of CNS Depressants. Management: Consider alternatives to the use of zuranolone with other CNS depressants or alcohol. If combined, consider a zuranolone dose reduction and monitor patients closely for increased CNS depressant effects. Risk D: Consider Therapy Modification
Long-term opioid use may cause secondary hypogonadism, which may lead to sexual dysfunction and infertility (Brennan 2013).
[US Boxed Warning]: Use is not recommended in pregnant women. Prolonged maternal use of opioids during pregnancy can cause neonatal withdrawal syndrome in the newborn, which may be life-threatening if not recognized and treated according to protocols developed by neonatology experts. If prolonged opioid therapy is required in a pregnant woman, ensure treatment is available and warn patient of risk to the neonate.
Refer to individual monographs for additional information.
Hydrocodone and chlorpheniramine are present in breast milk. Due to the potential for serious adverse reactions in the breastfed infant, breastfeeding is not recommended. See individual agents.
Relief of symptoms, respiratory and mental status; bowel function; signs/symptoms of misuse, abuse, and substance use disorder.
Hydrocodone: Binds to opiate receptors in the CNS, altering the perception of and response to pain; suppresses cough in medullary center; produces generalized CNS depression.
Chlorpheniramine: Competes with histamine for H1-receptor sites on effector cells in the GI tract, blood vessels, and respiratory tract.
Chlorpheniramine: See Chlorpheniramine monograph.
Hydrocodone:
Duration: 4 to 8 hours.
Metabolism: Hepatic; O-demethylation via primarily CYP2D6 to hydromorphone (major, active metabolite with ~10- to 33-fold higher or as much as a >100-fold higher binding affinity for the mu-opioid receptor than hydrocodone); N-demethylation via CYP3A4 to norhydrocodone (major metabolite); and ~40% of metabolism/clearance occurs via other non-CYP pathways, including 6-ketosteroid reduction to 6-alpha-hydrocol and 6-beta-hydrocol, and other elimination pathways (eg, fecal, biliary, intestinal, renal) (Hutchinson 2004; Volpe 2011; Zhou 2009).
Half-life elimination: ~4 to 5 hours.
Time to peak, plasma: ~3 hours (capsules, suspension).
Excretion: Urine (26% of single dose in 72 hours, with ~12% as unchanged drug, 5% as norhydrocodone, 4% as conjugated hydrocodone, 3% as 6-hydrocodol, and 0.21% as conjugated 6-hydromorphol (Zhou 2009).
