Brompheniramine Pediatric Dosing
Brompheniramine should be dosed based on age-specific weight bands, with children 6-12 years receiving 5 mL (1 teaspoonful) every 4 hours, children 2-6 years receiving 2.5 mL (½ teaspoonful) every 4 hours, and infants 6 months to 2 years requiring physician-established dosing, not exceeding 6 doses in 24 hours. 1
Age-Based Dosing Regimen
The FDA-approved dosing for brompheniramine oral solution follows a clear age-stratified approach 1:
- Ages 12 years and older: 10 mL (2 teaspoonfuls) every 4 hours
- Ages 6 to under 12 years: 5 mL (1 teaspoonful) every 4 hours
- Ages 2 to under 6 years: 2.5 mL (½ teaspoonful) every 4 hours
- Infants 6 months to under 2 years: Dosage must be established by a physician
- Maximum frequency: Do not exceed 6 doses in 24 hours 1
Pharmacokinetic Considerations Supporting This Dosing
The age-based dosing strategy is pharmacokinetically sound because brompheniramine demonstrates similar peak concentrations (Cmax) across pediatric age groups when age-appropriate doses are used. 2 Research using doses ranging from 1-4 mg based on age and weight achieved comparable drug exposure across children aged 2-17 years, with AUC values only 15-30% higher in older children 2.
Key pharmacokinetic findings that validate the dosing approach 2:
- Terminal elimination half-life: Approximately 12-15 hours across all pediatric age groups, supporting every 4-6 hour dosing 3, 2
- Time to peak concentration: 3.2 hours in children (mean age 9.5 years) 3
- Duration of action: Single doses produce significant histamine wheal and flare suppression from 0.5-30 hours, with maximum inhibition at 6-12 hours 3
- Clearance and volume of distribution: Both increase proportionally with age when allometrically scaled, eliminating the need for complex weight-based calculations 2
Critical Dosing Principles for Pediatric Patients
Children are not simply small adults and require age-specific dosing rather than simple weight-based scaling from adult doses. 4 The 4-fold dose range used in brompheniramine's age-based nomogram (from 2.5 mL to 10 mL) appropriately accounts for developmental pharmacokinetic differences 2.
Important considerations:
- Maturation matters most in infants: Children 2 years and older are pharmacokinetically mature and differ from adults primarily in size, while neonates and young infants have immature elimination pathways requiring physician supervision 4
- Sedation risk: Sedation is the most common adverse effect and appears more prevalent in the 2-5 year age group, warranting careful monitoring in younger children 2
- Avoid simple mg/kg scaling: Direct weight-based scaling from adult doses results in underdosing in children and overdosing in neonates 4