Chlorpheniramine, Pseudoephedrine, and Codeine

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Liquid, Oral:

Tricode AR: Chlorpheniramine maleate 2 mg, pseudoephedrine hydrochloride 30 mg, and codeine phosphate 8 mg per 5 mL (473 mL [DSC]) [dye free, ethanol free, gluten free, sugar free; contains propylene glycol; berry vanilla flavor]

Phenylhistine DH: Chlorpheniramine maleate 2 mg, pseudoephedrine hydrochloride 30 mg, and codeine phosphate 10 mg per 5 mL (120 mL [DSC], 480 mL [DSC]) [contains ethanol 5.3%, menthol, sodium benzoate]

Pharmacology

Mechanism of Action

Codeine: Binds to opioid receptors in the CNS, causing inhibition of ascending pain pathways, altering the perception of and response to pain; causes cough suppression by direct central action in the medulla; produces generalized CNS depression.

Chlorpheniramine: A propylamine derivative antihistamine drug (H₁ receptor antagonist) that also possesses anticholinergic and sedative activity. It prevents released histamine from dilating capillaries and causing edema of the respiratory mucosa.

Pseudoephedrine: Directly stimulates alpha-adrenergic receptors of respiratory mucosa causing vasoconstriction; directly stimulates beta-adrenergic receptors causing bronchial relaxation.

Use: Labeled Indications

Cough and upper respiratory allergy symptoms: Temporary relief of symptoms (runny nose, sneezing, itching of nose or throat, itchy/watery eyes, cough due to minor throat and bronchial irritation, nasal congestion, reduces swelling of nasal passages) associated with the common cold, allergic rhinitis, or other upper respiratory allergies.

Contraindications

OTC labeling: When used for self-medication, do not use in children <2 years; use with or within 14 days of stopping a monoamine oxidase inhibitor (MAO) inhibitor therapy; sedation in children; chronic pulmonary disease or shortness of breath

Documentation of allergenic cross-reactivity for sympathomimetics, antihistamines, and morphine and related agents is limited. However, because of similarities in chemical structure and/or pharmacologic actions, the possibility of cross-sensitivity cannot be ruled out with certainty.

Dosage and Administration

Dosing: Adult

Cough and upper respiratory allergy symptoms: Oral:

Chlorpheniramine 2 mg/codeine 8 mg/pseudoephedrine 30 mg per 5 mL: 10 mL every 4 to 6 hours (maximum: 40 mL/24 hours)

Chlorpheniramine 2 mg/codeine 10 mg/pseudoephedrine 30 mg per 5 mL: 10 mL every 4 hours (maximum: 40 mL/24 hours)

Dosing: Geriatric

Avoid use (Beers Criteria [AGS 2019]).

Dosing: Pediatric

Note: Due to risk of adverse effects (slowed or difficult breathing, misuse, abuse, addiction, 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 (AAP 2018; FDA 2018a; FDA 2018b).

Cough and upper respiratory allergy symptoms: Oral:

Children 6 to <12 years:

Chlorpheniramine 2 mg/codeine 8 mg/pseudoephedrine 30 mg per 5 mL: 5 mL every 4 to 6 hours (maximum: 20 mL/24 hours)

Chlorpheniramine 2 mg/codeine 10 mg/pseudoephedrine 30 mg per 5 mL: 5 mL every 4 hours (maximum: 20 mL/24 hours)

Children ≥12 years and Adolescents: Refer to adult dosing.

Administration

Administer liquid with an accurate measuring device; do not use a household teaspoon.

Storage

Store at 15°C to 30°C (59°F to 86°F).

Drug Interactions

Abiraterone Acetate: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Management: Avoid concurrent use of abiraterone with CYP2D6 substrates that have a narrow therapeutic index whenever possible. When concurrent use is not avoidable, monitor patients closely for signs/symptoms of toxicity. Consider therapy modification

Acetylcholinesterase Inhibitors: May diminish the therapeutic effect of Anticholinergic Agents. Anticholinergic Agents may diminish the therapeutic effect of Acetylcholinesterase Inhibitors. Monitor therapy

Aclidinium: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Ajmaline: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Alizapride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Alkalinizing Agents: May increase the serum concentration of Alpha-/Beta-Agonists (Indirect-Acting). Monitor therapy

Alpha1-Blockers: May diminish the vasoconstricting effect of Alpha-/Beta-Agonists. Similarly, Alpha-/Beta-Agonists may antagonize Alpha1-Blocker vasodilation. Monitor therapy

Alvimopan: Opioid Agonists may enhance the adverse/toxic effect 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. Consider therapy modification

Amantadine: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Amezinium: Antihistamines may enhance the stimulatory effect of Amezinium. Monitor therapy

Amphetamines: May enhance the analgesic effect of Opioid Agonists. Monitor therapy

Amphetamines: May diminish the sedative effect of Antihistamines. Monitor therapy

Anticholinergic Agents: May enhance the adverse/toxic effect of other Anticholinergic Agents. Monitor therapy

Anticholinergic Agents: May enhance the adverse/toxic effect of Opioid Agonists. Specifically, the risk for constipation and urinary retention may be increased with this combination. Monitor therapy

Asunaprevir: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Consider therapy modification

AtoMOXetine: May enhance the hypertensive effect of Sympathomimetics. AtoMOXetine may enhance the tachycardic effect of Sympathomimetics. Monitor therapy

Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination

Benzylpenicilloyl Polylysine: Antihistamines may diminish the diagnostic effect of Benzylpenicilloyl Polylysine. 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. Consider therapy modification

Benzylpenicilloyl Polylysine: Alpha-/Beta-Agonists may diminish the diagnostic effect of Benzylpenicilloyl Polylysine. Management: Consider use of a histamine skin test as a positive control to assess a patient's ability to mount a wheal and flare response. Consider therapy modification

Betahistine: Antihistamines may diminish the therapeutic effect of Betahistine. Monitor therapy

Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Consider therapy modification

Botulinum Toxin-Containing Products: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Bromopride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Bromperidol: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Carbonic Anhydrase Inhibitors: May increase the serum concentration of Alpha-/Beta-Agonists (Indirect-Acting). Monitor therapy

Chlormethiazole: May enhance the CNS depressant effect 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. Consider therapy modification

Chloroprocaine: May enhance the hypertensive effect of Alpha-/Beta-Agonists. Monitor therapy

Chlorphenesin Carbamate: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

Cimetropium: Anticholinergic Agents may enhance the anticholinergic effect of Cimetropium. Avoid combination

CNS Depressants: May enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists 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. Consider therapy modification

Cobicistat: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Cocaine (Topical): May enhance the hypertensive effect of Sympathomimetics. Management: Consider alternatives to use of this combination when possible. Monitor closely for substantially increased blood pressure or heart rate and for any evidence of myocardial ischemia with concurrent use. Consider therapy modification

CYP2D6 Inhibitors (Moderate): May diminish the therapeutic effect of Codeine. These CYP2D6 inhibitors may prevent the metabolic conversion of codeine to its active metabolite morphine. Monitor therapy

CYP2D6 Inhibitors (Strong): May diminish the therapeutic effect of Codeine. These CYP2D6 inhibitors may prevent the metabolic conversion of codeine to its active metabolite morphine. Consider therapy modification

CYP3A4 Inducers (Moderate): May decrease serum concentrations of the active metabolite(s) of Codeine. Monitor therapy

CYP3A4 Inducers (Strong): May decrease serum concentrations of the active metabolite(s) of Codeine. Monitor therapy

CYP3A4 Inhibitors (Moderate): May increase serum concentrations of the active metabolite(s) of Codeine. Monitor therapy

CYP3A4 Inhibitors (Strong): May increase serum concentrations of the active metabolite(s) of Codeine. Monitor therapy

Dacomitinib: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Management: Avoid concurrent use of dacomitinib with CYP2D6 subtrates that have a narrow therapeutic index. Consider therapy modification

Darunavir: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Desmopressin: Opioid Agonists may enhance the adverse/toxic effect of Desmopressin. Monitor therapy

Dimethindene (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Diuretics: Opioid Agonists may enhance the adverse/toxic effect of Diuretics. Opioid Agonists may diminish the therapeutic effect of Diuretics. Monitor therapy

Doxofylline: Sympathomimetics may enhance the adverse/toxic effect of Doxofylline. Monitor therapy

Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Consider therapy modification

Eluxadoline: Opioid Agonists may enhance the constipating effect of Eluxadoline. Avoid combination

Eluxadoline: Anticholinergic Agents may enhance the constipating effect of Eluxadoline. Avoid combination

Ergot Derivatives: May enhance the hypertensive effect of Alpha-/Beta-Agonists. Ergot Derivatives may enhance the vasoconstricting effect of Alpha-/Beta-Agonists. Exceptions: Ergoloid Mesylates; Nicergoline. Avoid combination

Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Consider therapy modification

Fosphenytoin-Phenytoin: Chlorpheniramine may increase the serum concentration of Fosphenytoin-Phenytoin. Monitor therapy

Gastrointestinal Agents (Prokinetic): Anticholinergic Agents may diminish the therapeutic effect of Gastrointestinal Agents (Prokinetic). Monitor therapy

Gastrointestinal Agents (Prokinetic): Opioid Agonists may diminish the therapeutic effect of Gastrointestinal Agents (Prokinetic). Monitor therapy

Glucagon: Anticholinergic Agents may enhance the adverse/toxic effect of Glucagon. Specifically, the risk of gastrointestinal adverse effects may be increased. Monitor therapy

Glycopyrrolate (Oral Inhalation): Anticholinergic Agents may enhance the anticholinergic effect of Glycopyrrolate (Oral Inhalation). Avoid combination

Glycopyrronium (Topical): May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Guanethidine: May enhance the arrhythmogenic effect of Sympathomimetics. Guanethidine may enhance the hypertensive effect of Sympathomimetics. Monitor therapy

Hyaluronidase: Antihistamines may diminish the therapeutic effect of Hyaluronidase. Management: Patients receiving antihistamines (particularly at larger doses) may not experience the desired clinical response to standard doses of hyaluronidase. Larger doses of hyaluronidase may be required. Consider therapy modification

HYDROcodone: CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Avoid concomitant use of hydrocodone 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. Consider therapy modification

Imatinib: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Iobenguane Radiopharmaceutical Products: Alpha-/Beta-Agonists (Indirect-Acting) may diminish the therapeutic effect of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Avoid combination

Ipratropium (Oral Inhalation): May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Itopride: Anticholinergic Agents may diminish the therapeutic effect of Itopride. Monitor therapy

Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

Lemborexant: May enhance the CNS depressant effect 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. Consider therapy modification

Levosulpiride: Anticholinergic Agents may diminish the therapeutic effect of Levosulpiride. Avoid combination

Lofexidine: May enhance the CNS depressant effect of CNS Depressants. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Monitor therapy

Lumefantrine: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Consider therapy modification

MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Monitor therapy

Minocycline (Systemic): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Mirabegron: Anticholinergic Agents may enhance the adverse/toxic effect of Mirabegron. Monitor therapy

Monoamine Oxidase Inhibitors: May enhance the adverse/toxic effect of Codeine. Avoid combination

Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Nalmefene: May diminish the therapeutic effect of Opioid Agonists. Management: Avoid the concomitant use of nalmefene and opioid agonists. Discontinue nalmefene 1 week prior to any anticipated use of opioid agonistss. If combined, larger doses of opioid agonists will likely be required. Consider therapy modification

Naltrexone: May diminish the therapeutic effect of Opioid Agonists. Management: Seek therapeutic alternatives to opioids. See full drug interaction monograph for detailed recommendations. Consider therapy modification

Nitroglycerin: Anticholinergic Agents may decrease the absorption of Nitroglycerin. Specifically, anticholinergic agents may decrease the dissolution of sublingual nitroglycerin tablets, possibly impairing or slowing nitroglycerin absorption. Monitor therapy

Opioid Agonists: CNS Depressants may enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists 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. Consider therapy modification

Opioids (Mixed Agonist / Antagonist): May diminish the analgesic effect 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. Avoid combination

Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination

Oxatomide: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Oxomemazine: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

OxyCODONE: CNS Depressants may enhance the CNS depressant effect 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. Consider therapy modification

Panobinostat: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination

Peginterferon Alfa-2b: May decrease the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Peginterferon Alfa-2b may increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Pegvisomant: Opioid Agonists may diminish the therapeutic effect of Pegvisomant. Monitor therapy

Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification

Perhexiline: CYP2D6 Substrates (High risk with Inhibitors) may increase the serum concentration of Perhexiline. Perhexiline may increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

PHENobarbital: May enhance the CNS depressant effect of Codeine. PHENobarbital may decrease the serum concentration of Codeine. Management: Avoid use of codeine and phenobarbital when possible. Monitor for respiratory depression/sedation. Because phenobarbital is also a strong CYP3A4 inducer, monitor for decreased codeine efficacy and withdrawal if combined. Consider therapy modification

Piribedil: CNS Depressants may enhance the CNS depressant effect of Piribedil. Monitor therapy

Pitolisant: Antihistamines may diminish the therapeutic effect of Pitolisant. Avoid combination

Potassium Chloride: Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Chloride. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium chloride. Avoid combination

Potassium Citrate: Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Citrate. Avoid combination

Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Monitor therapy

Pramlintide: May enhance the anticholinergic effect of Anticholinergic Agents. These effects are specific to the GI tract. Consider therapy modification

Primidone: May enhance the CNS depressant effect of Codeine. Primidone may decrease the serum concentration of Codeine. Management: Avoid use of codeine and primidone when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased codeine efficacy and withdrawal if combined. Consider therapy modification

QuiNINE: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Monitor therapy

Ramosetron: Anticholinergic Agents may enhance the constipating effect of Ramosetron. Monitor therapy

Ramosetron: Opioid Agonists may enhance the constipating effect of Ramosetron. Monitor therapy

Revefenacin: Anticholinergic Agents may enhance the anticholinergic effect of Revefenacin. Avoid combination

ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Monitor therapy

Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Monitor therapy

Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy

Secretin: Anticholinergic Agents may diminish the therapeutic effect of Secretin. Management: Avoid concomitant use of anticholinergic agents and secretin. Discontinue anticholinergic agents at least 5 half-lives prior to administration of secretin. Consider therapy modification

Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Monitor therapy

Serotonergic Agents (High Risk): Opioid Agonists may enhance the serotonergic effect 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. Monitor therapy

Serotonin/Norepinephrine Reuptake Inhibitors: May enhance the tachycardic effect of Alpha-/Beta-Agonists. Serotonin/Norepinephrine Reuptake Inhibitors may enhance the vasopressor effect of Alpha-/Beta-Agonists. Consider therapy modification

Sincalide: Drugs that Affect Gallbladder Function may diminish the therapeutic effect of Sincalide. Management: Consider discontinuing drugs that may affect gallbladder motility prior to the use of sincalide to stimulate gallbladder contraction. Consider therapy modification

Sodium Oxybate: May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated. Consider therapy modification

Solriamfetol: Sympathomimetics may enhance the hypertensive effect of Solriamfetol. Monitor therapy

Somatostatin Analogs: May decrease the metabolism of Codeine. The formation of two major codeine metabolites (morphine and norcodeine) may be impaired by somatostatin analogs. Monitor therapy

Spironolactone: May diminish the vasoconstricting effect of Alpha-/Beta-Agonists. Monitor therapy

Succinylcholine: May enhance the bradycardic effect of Opioid Agonists. Monitor therapy

Suvorexant: CNS Depressants may enhance the CNS depressant effect 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. Consider therapy modification

Sympathomimetics: May enhance the adverse/toxic effect of other Sympathomimetics. Monitor therapy

Tapentadol: May enhance the CNS depressant effect of CNS Depressants. Management: Avoid concomitant use of tapentadol 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. Consider therapy modification

Tedizolid: May enhance the hypertensive effect of Sympathomimetics. Tedizolid may enhance the tachycardic effect of Sympathomimetics. Monitor therapy

Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Tetrahydrocannabinol and Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination

Thiazide and Thiazide-Like Diuretics: Anticholinergic Agents may increase the serum concentration of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Thioridazine: Chlorpheniramine may enhance the arrhythmogenic effect of Thioridazine. Thioridazine may increase the serum concentration of Chlorpheniramine. Management: Avoid this combination when possible. If used, monitor closely for arrhythmia as well as general toxicity of chlorpheniramine. Consider therapy modification

Tiotropium: Anticholinergic Agents may enhance the anticholinergic effect of Tiotropium. Avoid combination

Tricyclic Antidepressants: May enhance the vasopressor effect of Alpha-/Beta-Agonists. Management: Avoid, if possible, the use of alpha-/beta-agonists in patients receiving tricyclic antidepressants. If combined, monitor for evidence of increased pressor effects and consider reductions in initial dosages of the alpha-/beta-agonist. Consider therapy modification

Umeclidinium: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Urinary Acidifying Agents: May decrease the serum concentration of Alpha-/Beta-Agonists (Indirect-Acting). Monitor therapy

Zolpidem: CNS Depressants may enhance the CNS depressant effect 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. Consider therapy modification

Test Interactions

See individual agents.

Adverse Reactions

Also see individual agents.

<1%, postmarketing, and/or case reports: Hypogonadism (Brennan 2013; Debono 2011)

Warnings/Precautions

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 which require mental alertness (eg, operating machinery or driving).
• Constipation: Codeine may cause or aggravate constipation; chronic use may result in obstructive bowel disease, particularly in those with underlying intestinal motility disorders.
• Phenanthrene hypersensitivity: Use codeine with caution in patients with hypersensitivity reactions to other phenanthrene-derivative opioid agonists (hydrocodone, hydromorphone, levorphanol, oxycodone, oxymorphone).
• Respiratory depression: Codeine may cause dose-related respiratory depression. This risk is increased in elderly patients and debilitated patients; use with caution postoperatively, in patients with pulmonary disease or shortness of breath, or when ventilator function is depressed.

Disease-related concerns:

• Abdominal conditions: Codeine may obscure diagnosis or clinical course of patients with acute abdominal conditions.
• Adrenal insufficiency: Use codeine with caution in patients with adrenal insufficiency, including Addison disease. Long-term opioid use may cause secondary hypogonadism, which may lead to sexual dysfunction, infertility, mood disorders, and osteoporosis (Brennan 2013).
• Biliary tract impairment: Use codeine with caution in patients with biliary tract dysfunction, including acute pancreatitis; may cause constriction of sphincter of Oddi; may increase amylase/lipase levels.
• Cardiovascular disease: Use with caution in patients with cardiovascular disease (including hypertension and ischemic heart disease).
• CNS depression/coma: Avoid use in patients with CNS depression or coma as these patients are susceptible to intracranial effects of CO₂ retention.
• Diabetes: Use pseudoephedrine with caution in patients with diabetes mellitus.
• Gastrointestinal obstruction: Avoid use of codeine in patients with gastrointestinal obstruction, particularly paralytic ileus; chronic use may result in obstructive bowel disease.
• Head trauma: Avoid use in patients with head injury, intracranial lesions, or elevated intracranial pressure.
• Hepatic impairment: Use with caution in patients with severe hepatic impairment.
• Increased intraocular pressure/glaucoma: Use pseudoephedrine with caution in patients with increased intraocular pressure or angle-closure glaucoma.
• Obesity: Use codeine with caution in patients who are morbidly obese.
• Prostatic hyperplasia/urinary obstruction: Use with caution in patients with prostatic hyperplasia and/or GU obstruction.
• Renal impairment: Use with caution in patients with severe renal impairment.
• Respiratory disease: Use with caution in patients with pulmonary disease (eg, asthma, chronic bronchitis, emphysema, smoking) or persistent or chronic cough; dose-related respiratory depression occurs.
• Seizure disorder: Use with caution in patients with seizure disorder; may produce CNS stimulation.
• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction.

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• CYP2D6 “ultrarapid metabolizers”: Use codeine with caution in patients with two or more copies of the variant CYP2D6*2 allele; may have extensive conversion to morphine and thus increased opioid-mediated effects. Avoid the use of codeine in these patients; consider alternative analgesics such as morphine or a nonopioid agent (Crews 2012). The occurrence of this phenotype is seen in 0.5% to 1% of Chinese and Japanese, 0.5% to 1% of Hispanics, 1% to 10% of Caucasians, 3% of African-Americans, and 16% to 28% of North Africans, Ethiopians, and Arabs.
• Debilitated patients: Use with caution in debilitated patients; there is a greater potential for critical respiratory depression, even at therapeutic dosages.
• Elderly: Use with caution in the elderly; may be more sensitive to adverse effects.
• Neonates: Neonatal withdrawal syndrome: After chronic maternal exposure to opioids, neonatal withdrawal syndrome may occur in the newborn; monitor neonate closely. 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. Opioid withdrawal syndrome in the neonate, unlike in adults, may be life-threatening and should be treated according to protocols developed by neonatology experts.
• 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 (AAP 2018; FDA 2018a; FDA 2018b). Respiratory depression and death have occurred in children who received codeine following tonsillectomy and/or adenoidectomy and were found to have evidence of being ultra-rapid metabolizers of codeine due to a CYP2D6 polymorphism. Deaths have also occurred in nursing infants after being exposed to high concentrations of morphine in breast milk because the mothers were ultra-rapid metabolizers. Antihistamines may cause excitation in young children.

Dosage form specific issues:

• Benzyl alcohol and derivatives: Some dosage forms may contain sodium benzoate/benzoic acid; benzoic acid (benzoate) is a metabolite of benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity ("gasping syndrome") in neonates; the "gasping syndrome" consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors 2001); avoid or use dosage forms containing benzyl alcohol derivative with caution in neonates. 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 codeine with caution in patients with a history of drug abuse or acute alcoholism; potential for drug dependency exists. Tolerance and psychological and physical dependence may occur with prolonged use. Health care provider should be alert to the potential for abuse, misuse, and diversion.
• Appropriate use: A special measuring device should be used to measure accurate doses for children <6 years of age. Calibrated oral syringes are most accurate. Do not exceed the recommended dosages.
• Self-medication (OTC use): When used for self-medication (OTC), patients with a breathing problem or persistent or chronic cough (associated with chronic bronchitis, emphysema, asthma or smoking) and/or productive cough (eg, excessive amounts of phlegm) should be evaluated by a health care provider prior to use. Discontinue use and notify health care provider if symptoms do not get better within 7 days or are accompanied by fever; cough last more than 7 days, comes back or occurs with fever, rash or headache that lasts; if nervousness, dizziness, or trouble sleeping occur.

Monitoring Parameters

Relief of symptoms; respiratory and mental status, blood pressure; bowel function

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
• Patient may experience anxiety, trouble sleeping, or sweating a lot. Have patient report immediately to prescriber severe dizziness, passing out, chest pain, fast heartbeat, difficulty breathing, slow breathing, shallow breathing, noisy breathing, severe fatigue, confusion, abnormal heartbeat, sensing things that seem real but are not, mood changes, seizures, severe abdominal pain, severe headache, difficult urination, tremors, vision changes, severe nausea, severe vomiting, severe constipation, or severe loss of strength and energy (HCAHPS).
• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.