Home Drug Guide Chlorpheniramine Maleate; Codeine Phosphate

Drug Guide

Generic Name

Chlorpheniramine Maleate; Codeine Phosphate

Brand Names Tuxarin Er

Classification

Therapeutic: Cough suppressant/antihistamine

Pharmacological: Antihistamine (Chlorpheniramine), Opioid analgesic (Codeine)

FDA Approved Indications

Relief of cough and upper respiratory allergy symptoms

Mechanism of Action

Chlorpheniramine is an antihistamine that blocks H1 receptors, reducing allergic symptoms. Codeine is an opioid that suppresses the cough center in the brain, reducing the cough reflex.

Dosage and Administration

Adult: Dose varies; typically 4 mg of chlorpheniramine and 10-20 mg of codeine every 4-6 hours as needed, not exceeding recommended daily limits.

Pediatric: Use is generally not recommended under age 12 due to safety concerns.

Geriatric: Begin at lower doses; monitor for sedation and respiratory depression.

Renal Impairment: Adjust dosage as needed; use with caution.

Hepatic Impairment: Use with caution; consider lower doses.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Distributed throughout body tissues; crosses the blood-brain barrier.

Metabolism: Liver metabolism for both components, especially codeine via CYP2D6.

Excretion: Renal excretion of metabolites.

Half Life: Chlorpheniramine: approximately 20 hours; Codeine: approximately 3 hours.

Contraindications

Hypersensitivity to components
ACUTE ASTHMA ATTACKS
Respiratory depression

Precautions

Use with caution in patients with respiratory depression, asthma, liver impairment, or prone to CNS depression. Avoid use in children under 12 due to risk of respiratory depression and death.

Adverse Reactions - Common

Drowsiness (Common)
Dizziness (Common)
Dry mouth (Common)

Adverse Reactions - Serious

Respiratory depression (Rare)
Drug dependence (Rare)
Allergic reactions (Rare)

Drug-Drug Interactions

CNS depressants, including alcohol, benzodiazepines.

Drug-Food Interactions

Alcohol may enhance sedative effects.

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor respiratory status, level of sedation, and behavioral changes.

Diagnoses:

Risk for respiratory depression
Sedation

Implementation: Use lowest effective dose, avoid alcohol, monitor for adverse effects.

Evaluation: Assess effectiveness in symptom relief and absence of adverse effects.

Patient/Family Teaching

Do not operate heavy machinery or drive until shows how the drug affects you.
Report signs of respiratory depression, excessive sedation, or allergic reactions.
Avoid alcohol and CNS depressants.
Follow dosing instructions carefully.

Special Considerations

Black Box Warnings:

Serious or life-threatening respiratory depression in children under 12 and certain populations.
Potential for addiction, abuse, and misuse.

Genetic Factors: Codeine metabolism affected by CYP2D6 polymorphisms, impacting efficacy and safety.

Lab Test Interference: No significant interference generally noted.

Overdose Management

Signs/Symptoms: Respiratory depression, drowsiness, confusion, hypotension, coma.

Treatment: Maintain airway, support breathing, activated charcoal if recent ingestion, naloxone for opioid overdose.

Storage and Handling

Storage: Store at room temperature away from light and moisture.

Stability: Stable under recommended storage conditions.