Pediatric Dosing of Zyrtec (Cetirizine)
For pediatric patients, Zyrtec (cetirizine) should be dosed according to age: children 6 years and older should receive 10 mg once daily, children 2-5 years should receive 2.5 mg (½ teaspoon) to 5 mg (1 teaspoon) once daily, and children 6-11 months should receive 2.5 mg (½ teaspoon) once daily.
Age-Based Dosing Recommendations
Children 6 years and older
- Dose: 10 mg once daily
- Alternative: 5 mg once daily may be appropriate for less severe symptoms 1, 2
- Formulation: Tablets (5 mg, 10 mg) or liquid (5 mg/5 mL)
Children 2-5 years
- Dose: 2.5-5 mg once daily
- Formulation: Liquid (5 mg/5 mL)
- 2.5 mg = ½ teaspoon
- 5 mg = 1 teaspoon
Children 6-11 months
- Dose: 2.5 mg (½ teaspoon) once daily 3
- Formulation: Liquid (5 mg/5 mL)
Children under 6 months
- Not recommended without physician guidance
- Limited safety data in this age group
Clinical Considerations
Efficacy
- Cetirizine is effective for allergic rhinitis symptoms in children as young as 6 months 3
- Studies have shown good symptom control with once-daily dosing in children 2-6 years old 4
Safety Profile
- Cetirizine has a favorable safety profile in pediatric patients 5, 3
- As a second-generation antihistamine, it causes less sedation than first-generation alternatives 1
- No QT interval prolongation has been observed in infants, making it safer than some older antihistamines 3
Common Side Effects
- Drowsiness (less common than with first-generation antihistamines)
- Dry mouth
- Headache
- Fatigue
Special Populations
- Renal impairment: Dose reduction may be necessary in children with kidney disease 2
- Hepatic impairment: Consult physician before use in children with liver disease 2
Practical Administration Tips
- Cetirizine can be given with or without food
- Liquid formulation is ideal for younger children who cannot swallow tablets
- Consistent timing of daily dose helps maintain therapeutic levels
- For allergic rhinitis, best results are achieved with regular rather than as-needed use
Monitoring
- Observe for unusual drowsiness, especially when initiating therapy
- Monitor for symptom improvement within 1-3 days of starting treatment
- Assess periodically for continued need of medication
Cetirizine is one of the safer antihistamine options for pediatric patients, with minimal risk of cardiotoxicity compared to older antihistamines and a lower incidence of sedation than first-generation options 5. Even in cases of accidental overdose, serious adverse effects are rare, with drowsiness being the primary concern 6.