Nurses Compass
Drug Guide
Bromodiphenhydramine Hydrochloride
Classification
Therapeutic: Antihistamine, Anticholinergic
Pharmacological: H1-antihistamine, Anticholinergic
FDA Approved Indications
- Allergic rhinitis
- Seasonal allergic conjunctivitis
- Urticaria (hives)
Mechanism of Action
Bromodiphenhydramine is an H1 antihistamine that blocks the effects of histamine at H1 receptor sites, reducing allergy symptoms. Its anticholinergic properties also contribute to drying effects such as reduced mucus secretion.
Dosage and Administration
Adult: Typically 25-50 mg every 4-6 hours as needed, not exceeding 300 mg/day
Pediatric: Dosage varies by age; generally 6-12 mg every 4-6 hours, not exceeding 12 mg/kg/day or as directed by physician
Geriatric: Start with lower doses due to increased sensitivity; monitor for anticholinergic side effects and sedation
Renal Impairment: Adjust dosing based on severity of impairment; consult specific guidelines
Hepatic Impairment: Use with caution; dose adjustments may be necessary depending on hepatic function.
Pharmacokinetics
Absorption: Well absorbed following oral administration
Distribution: Widely distributed including into tissues and body fluids
Metabolism: Metabolized in the liver (CYP450 pathway)
Excretion: Excreted primarily in urine, both as metabolites and unchanged drug
Half Life: Approximately 10-12 hours, but may be prolonged in hepatic impairment
Contraindications
- Known hypersensitivity to bromodiphenhydramine or other antihistamines
- Newborns and premature infants
Precautions
- Use with caution in patients with glaucoma, urinary retention, prostatic hypertrophy, or gastric retention; avoid in patients with asthma or COPD without medical advice; caution in elderly due to anticholinergic effects
Adverse Reactions - Common
- Sedation or drowsiness (Common)
- Dry mouth (Common)
- Dizziness (Uncommon)
Adverse Reactions - Serious
- Seizures (rare) (Rare)
- Cardiac arrhythmias (rare) (Rare)
- Allergic reactions including rash, pruritus (rare) (Rare)
Drug-Drug Interactions
- Additive sedative effects with other CNS depressants (e.g., alcohol, benzodiazepines)
- Anticholinergic drugs may enhance anticholinergic side effects
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Monitor for effectiveness in relieving allergy symptoms; assess mental status, sedation levels, and respiratory status
Diagnoses:
- Risk for sedation and falls
- Impaired comfort related to allergy symptoms
Implementation: Administer with food if gastrointestinal upset occurs; instruct patient to avoid activities requiring alertness until response is known
Evaluation: Assess symptom relief and monitor for adverse effects regularly
Patient/Family Teaching
- Take medication exactly as prescribed; do not exceed recommended doses.
- Warn about possible drowsiness; avoid driving or operating heavy machinery until response is known.
- Caution to avoid alcohol and other CNS depressants.
- Report any signs of allergic reactions, severe side effects, or unusual symptoms.
Special Considerations
Black Box Warnings:
- None specific to this medication
Genetic Factors: Pharmacogenetic variations may influence metabolism and response
Lab Test Interference: None known
Overdose Management
Signs/Symptoms: Seizures, hallucinations, pupil dilation, dry mouth, flushing, tachycardia, urinary retention, hypotension, hallucinations, coma
Treatment: Supportive care; activated charcoal if ingestion is recent; intravenous fluids; management of agitation or seizures; cardiac monitoring
Storage and Handling
Storage: Store at room temperature, away from moisture, heat, and light
Stability: Stable for the duration of the expiration date when properly stored