Drug Guide
Dexbrompheniramine Maleate and Pseudoephedrine Sulfate
Classification
Therapeutic: Decongestant and Antihistamine combination
Pharmacological: Antihistamine (dexbrompheniramine) and Sympathomimetic decongestant (pseudoephedrine)
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
Assessment: Monitor for CNS depression or stimulation, blood pressure, and cardiac status.
Diagnoses:
- Ineffective airway clearance due to CNS effects.
- Risk of increased blood pressure or heart rate.
Implementation: Administer with food if gastrointestinal upset occurs, monitor patient closely for adverse effects.
Evaluation: Assess effectiveness in relieving nasal congestion and allergy symptoms; monitor for adverse reactions.
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.