BROMPHENIRAMINE MALEATE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for BROMPHENIRAMINE MALEATE (BROMPHENIRAMINE MALEATE).
Competitive antagonist of histamine at H1 receptor sites, suppressing histamine-induced vasodilation, increased capillary permeability, and bronchoconstriction.
| Metabolism | Hepatic via CYP450 enzymes (primarily CYP3A4 and CYP2D6) |
| Excretion | Renal (85-90% as metabolites, 5-10% unchanged); biliary/fecal <5%. |
| Half-life | Terminal half-life 22-25 hours; prolonged in hepatic impairment or elderly (up to 40 hours). |
| Protein binding | 40-55% bound, primarily to albumin. |
| Volume of Distribution | 9-12 L/kg; extensive tissue distribution, large Vd reflects high tissue binding. |
| Bioavailability | Oral: 60-80% due to first-pass metabolism; IM: near 100%; IV: 100%. |
| Onset of Action | Oral: 15-30 minutes; Intramuscular: 10-15 minutes; Intravenous: immediate. |
| Duration of Action | 4-6 hours (oral); 6-8 hours (parenteral); extended-release oral: up to 12 hours. |
| Molecular Weight | 319.23 |
| Action Class | First-generation antihistamine (alkylamine class) |
4 mg orally every 4-6 hours, not to exceed 24 mg/day. Alternatively, extended-release: 12 mg every 12 hours.
| Dosage form | TABLET |
| Renal impairment | No specific guidelines; use with caution in renal impairment (CrCl < 10 mL/min: increase dosing interval or avoid due to anticholinergic effects). |
| Liver impairment | No specific guidelines; use with caution in severe hepatic impairment (Child-Pugh class C) due to possible reduced clearance. |
| Pediatric use | Children 6-12 years: 2 mg every 4-6 hours, max 12 mg/day. Children 2-6 years: 0.5 mg/kg/day divided every 6-8 hours (max 6 mg/day). Not recommended under 2 years due to safety concerns. |
| Geriatric use | Initiate at lower doses (e.g., 4 mg every 6-8 hours) due to increased sensitivity to anticholinergic effects and risk of confusion, sedation, and falls. |
| 1st trimester | Limited human data; animal studies show no risk in first trimester. Avoid use unless clearly needed. |
| 2nd trimester | Limited human data; no known teratogenicity. Use only if benefit outweighs risk. |
| 3rd trimester | May cause respiratory depression in neonates if used near term. Avoid use in late pregnancy. |
Clinical note
Comprehensive clinical and safety monograph for BROMPHENIRAMINE MALEATE (BROMPHENIRAMINE MALEATE).
| Placental transfer | Crosses placenta; extent unknown. |
| Breastfeeding | Small amounts excreted into breast milk; may cause irritability or drowsiness in infant. Compatible with cautious use. |
| Lactation Rating |
■ FDA Black Box Warning
Not available
| Common Effects | Drowsiness, Dizziness, Dry mouth, Blurred vision, Urinary retention, Gastrointestinal disturbances |
| Serious Effects | Seizures, Respiratory depression, Cardiac arrhythmias (e.g., QT prolongation, torsades de pointes), Severe hypotension, Anaphylaxis |
Hypersensitivity to brompheniramine or any componentConcurrent use of MAO inhibitorsSevere hypertensionCoronary artery diseaseAngle-closure glaucomaSymptomatic prostatic hypertrophyStenosing peptic ulcerBladder neck obstructionNeonates and preterm infants
| Precautions | Avoid in patients with asthma or COPD due to anticholinergic effects, May cause drowsiness; avoid driving or operating machinery, Use caution in elderly, may cause confusion or urinary retention, Avoid concurrent use with CNS depressants |
| Food/Dietary |
Loading safety data…
| L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Limited human data; animal studies show no teratogenicity at therapeutic doses. Second and third trimesters: No evidence of major malformations; avoid near term due to risk of neonatal respiratory depression and anticholinergic effects. |
| Fetal Monitoring | Monitor maternal blood pressure, heart rate, and signs of sedation; assess fetal heart rate during third trimester use; observe neonate for respiratory depression, irritability, or feeding difficulties if used near delivery. |
| Fertility Effects | No known direct effects on human fertility; animal studies have not reported reproductive impairment at therapeutic doses. |
| Avoid alcohol and grapefruit juice; grapefruit may increase CNS depressant effects; consuming with food may delay absorption; no specific food restrictions other than avoiding alcohol. |
| Clinical Pearls | Brompheniramine maleate is a first-generation alkylamine antihistamine with strong sedative effects; avoid in elderly due to anticholinergic risks; use with caution in glaucoma, urinary retention, and asthma; maximal effect may take 1-2 hours after oral administration; combined with dextromethorphan and phenylephrine in common cold preparations. |
| Patient Advice | Drowsiness is common; avoid driving or operating machinery until you know how this medication affects you. · Take exactly as prescribed; do not exceed recommended dose. · Avoid alcohol and other CNS depressants (e.g., sedatives, tranquilizers) as they can increase drowsiness. · Notify your doctor if you have glaucoma, trouble urinating, asthma, or thyroid disease. · Dry mouth, nose, and throat may occur; use sugarless candy or gum for relief. |