What is the recommended loratadine syrup dosing for children of various ages, including weight‑based guidance and contraindication for children under 2 years?

Loratadine Syrup Dosing in Children

Loratadine syrup should be dosed at 5 mg (1 teaspoonful) once daily for children aged 2 to under 6 years, and 10 mg (2 teaspoonfuls) once daily for children 6 years and older, with use contraindicated in children under 2 years of age. 1

Age-Based Dosing Algorithm

Children Under 2 Years

• Loratadine is contraindicated in children under 2 years of age 1
• Parents should consult a physician before administering loratadine to infants and toddlers in this age group 1

Children 2 to Under 6 Years

• Dose: 5 mg (1 teaspoonful) once daily 1
• Maximum dose: Do not exceed 5 mg in 24 hours 1
• This dosing provides exposure similar to the adult 10 mg dose and has been validated in pharmacokinetic studies showing peak plasma concentrations of 7.78 ng/mL for loratadine and 5.09 ng/mL for its active metabolite desloratadine 2

Children 6 Years and Older

• Dose: 10 mg (2 teaspoonfuls) once daily 1
• Maximum dose: Do not exceed 10 mg in 24 hours 1

Special Populations Requiring Dose Adjustment

Hepatic or Renal Impairment

• Children with liver or kidney disease should consult a physician before using loratadine, as dose adjustments may be necessary 1
• The British Journal of Dermatology guidelines note that loratadine should be used with caution in severe renal impairment 3

Clinical Pharmacology Supporting These Doses

Pharmacokinetic Profile:

• Loratadine reaches peak plasma concentration in 1-2 hours, while its active metabolite desloratadine peaks at 2-4 hours 2, 4
• The elimination half-life is approximately 10 hours for loratadine and 20 hours for desloratadine, supporting once-daily dosing 4
• Duration of action is at least 24 hours with onset within 1 hour 4

Pediatric Exposure Data:

• In children aged 2-5 years receiving 5 mg, the area under the curve (AUC) was 16.7 ng×h/mL for loratadine and 87.2 ng×h/mL for desloratadine 2
• These exposure levels are comparable to adults receiving 10 mg doses, confirming appropriate dosing for efficacy 2, 5

Safety and Tolerability Evidence

Established Safety Profile:

• Multiple controlled trials demonstrate that loratadine syrup is well tolerated in children aged 2-11 years with no clinically significant adverse events 2, 6
• Electrocardiographic parameters remain unchanged compared to placebo, with no QT interval prolongation 2
• The incidence of adverse events in pediatric studies was comparable to or lower than placebo 2, 6

Common Pitfall to Avoid:

• Do not use weight-based dosing for loratadine in children, as the FDA-approved dosing is strictly age-based 1
• Unlike some antihistamines that use mg/kg calculations, loratadine uses fixed doses by age group for optimal safety and efficacy 1

Practical Administration Guidance

• Use only the enclosed dosing cup provided with the syrup formulation to ensure accurate measurement 1
• Loratadine syrup (1 mg/mL concentration) allows for easy administration in young children who cannot swallow tablets 2
• Once-daily dosing improves compliance compared to multiple-daily-dose antihistamines 4