Generic Name

Dexbrompheniramine Maleate and Pseudoephedrine Sulfate

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Classification

FDA Approved Indications

• Relief of nasal congestion associated with allergies, hay fever, or the common cold

Mechanism of Action

Dexbrompheniramine is an antihistamine that blocks histamine H1 receptors, reducing allergy symptoms. Pseudoephedrine is a sympathomimetic agent that constricts blood vessels in the nasal passages, leading to decreased swelling and congestion.

Dosage and Administration

Adult: Typically, 1 tablet every 4 to 6 hours as needed, not exceeding 6 doses per day.

Pediatric: Dosage varies; generally not recommended for children under 12 without physician guidance.

Geriatric: Use with caution; start at the lower end of the dosing spectrum due to potential sensitivity.

Renal Impairment: Adjust dosing; consult specific product instructions or healthcare provider.

Hepatic Impairment: Use with caution; no specific adjustments well-established.

Pharmacokinetics

Absorption: Rapidly absorbed from gastrointestinal tract

Distribution: Widely distributed in body tissues, crosses the blood-brain barrier

Metabolism: Metabolized in the liver (pseudoephedrine minimally metabolized)

Excretion: Excreted mainly in urine

Half Life: Approximately 4 to 6 hours for dexbrompheniramine; pseudoephedrine half-life varies from 4 to 8 hours depending on pH of urine and other factors

Contraindications

• Known hypersensitivity to antihistamines or sympathomimetic agents.
• Use in patients with angle-closure glaucoma, urinary retention, or severe hypertension.

Precautions

• Use cautiously in patients with cardiovascular disease, hypertension, hyperthyroidism, diabetes, or prostate enlargement.
• Use with caution in elderly due to increased sensitivity to anticholinergic effects.

Adverse Reactions - Common

• Drowsiness, dry mouth, dizziness (Common)
• Nervousness, insomnia (Common)

Adverse Reactions - Serious

• Respiratory depression, tachycardia, hallucinations (Rare)
• Seizures, hypersensitivity reactions (Rare)

Drug-Drug Interactions

• Other CNS depressants, MAO inhibitors, other adrenergic agents

Drug-Food Interactions

• Alcohol may enhance sedative effects

Drug-Herb Interactions

• Potential enhancement of hypertensive effects by ephedra

Nursing Implications

Patient/Family Teaching

• Take medication exactly as prescribed.
• Avoid alcohol and other CNS depressants.
• Do not operate heavy machinery until the effects are known.
• Report any adverse reactions or signs of allergic response.

Special Considerations

Black Box Warnings:

• Pseudoephedrine has potential for abuse (convert to methamphetamine) and cardiovascular stimulation.

Genetic Factors: Consider genetic differences affecting metabolism, particularly CYP450 interactions.

Lab Test Interference: Pseudoephedrine can potentially elevate blood pressure readings.

Overdose Management

Signs/Symptoms: Severe agitation, hallucinations, tremors, tachycardia, hypertension, CNS depression in case of overdose of antihistamine.

Treatment: Supportive care, activated charcoal if ingestion is recent, and symptomatic management. Specific antidote not available.

Storage and Handling

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

Stability: Stable under recommended conditions, check manufacturer instructions.