Levocetirizine Pediatric Dosing
Levocetirizine is dosed at 0.125 mg/kg twice daily in children aged 6 months to 5 years, based on FDA labeling and pharmacokinetic studies demonstrating this provides adequate plasma levels and symptom control. 1, 2
Age-Based Dosing Guidelines
Children 6-11 months
- Dose: 1.25 mg once daily 1, 3
- This translates to approximately 0.125 mg/kg for infants in this age range
- Safety and tolerability confirmed in randomized controlled trials 3
Children 1-5 years
- Dose: 1.25 mg twice daily (total 2.5 mg/day) 1, 2, 3
- This equals 0.125 mg/kg per dose, given twice daily 2
- Pharmacokinetic studies demonstrate peak plasma levels of 286 ± 68 ng/ml with elimination half-life of 4.1 hours, supporting twice-daily dosing in this age group 2
Children 6-11 years
Children ≥12 years and adults
- Dose: 5 mg once daily 1
Key Pharmacokinetic Considerations
Young children require relatively higher mg/kg doses and more frequent dosing compared to adults due to rapid clearance. 4, 2
- Oral clearance increases by 0.044 L/h/kg with increasing body weight 4
- Volume of distribution increases by 0.639 L/kg with body weight 4
- The shorter elimination half-life (4.1 hours) in toddlers versus adults necessitates twice-daily dosing for sustained effect 2
Clinical Efficacy Data
Levocetirizine at 0.125 mg/kg twice daily produces near-complete suppression of histamine-induced wheal and flare responses in young children. 2
- Median wheal inhibition: 100% at steady state 2
- Median flare inhibition: 99.6% at steady state 2
- Trough plasma levels of 78-110 ng/ml maintain therapeutic effect 2
Safety Profile
Long-term safety has been established in children as young as 6 months, with an 18-month study showing no adverse effects on growth, development, or laboratory parameters. 5
- Adverse event rates similar to placebo in infants 6-11 months and children 1-5 years 3
- No clinically relevant changes in vital signs, ECG parameters (including QT interval), or laboratory values 3
- No impact on height, weight, or developmental milestones over 18 months of continuous use 5
- Discontinuation due to adverse events: 2.0% (levocetirizine) vs 1.2% (placebo) 5
Important Caveats
Do not use levocetirizine in children under 6 months of age—FDA labeling explicitly contraindicates use in this population. 1
Patients with kidney disease should not use levocetirizine without dose adjustment, as renal excretion is the primary elimination pathway. 1
The evidence base for levocetirizine in children is substantially stronger than for most antihistamines, making it a preferred choice when pharmacologic treatment is indicated. 6