What is the recommended dosage of cetirizine (antihistamine) for a 12-month-old child?

Cetirizine Dosage for a 12-Month-Old Child

The recommended dosage of cetirizine for a 12-month-old child is 2.5 mg (half of a 5 mg tablet) once daily. 1

Dosing Guidelines for Cetirizine in Infants

For infants aged 12 months, cetirizine can be safely administered with appropriate dosing:

• Age-specific dosing:

  • 6-11 months: 0.25 mg/kg twice daily 2
  • 12-23 months: 0.125 mg/kg twice daily or 2.5 mg once daily 1, 3

• Weight-based considerations:

  • For a typical 12-month-old (8-12 kg), this translates to approximately 2.5 mg daily
  • The dose should be adjusted based on the child's exact weight if significantly different from typical weight for age

Administration Recommendations

• Cetirizine is available as:

  • Oral solution (5 mg/5 mL)
  • Chewable tablets (5 mg)
  • Regular tablets (5 mg, 10 mg)

• For a 12-month-old, the oral solution is the preferred formulation for accurate dosing

• Administer with or without food (though giving with food may improve gastrointestinal tolerability)

• Once-daily dosing is typically sufficient, but can be divided into twice-daily dosing if needed for symptom control

Safety Profile in Infants

Cetirizine has been specifically studied in infants and demonstrates a favorable safety profile:

• A randomized, double-blind, placebo-controlled study in infants 6-11 months showed no significant differences in adverse events between cetirizine and placebo 2
• Cetirizine has a lower incidence of sedation compared to first-generation antihistamines 1
• No cardiac concerns (no QT interval prolongation) were observed in infant studies 2

Monitoring and Precautions

• Watch for potential side effects:

  • Mild drowsiness (less common than with first-generation antihistamines)
  • Dry mouth
  • Irritability

• Special considerations:

  • Renal function: Dose should be reduced in moderate renal impairment and avoided in severe renal impairment 1
  • Avoid concurrent use of other medications that cause sedation

Clinical Pearls

• Cetirizine is preferred over first-generation antihistamines due to lower risk of sedation and anticholinergic effects 1
• The pharmacokinetics of cetirizine in young children differ from adults, with more rapid clearance requiring weight-based dosing 4
• Levocetirizine (the active enantiomer of cetirizine) studies support the safety of cetirizine in this age group 3