Clarithromycin Dosing for a 2-Year-Old Child Weighing 17 kg
Give 2.5 mL of clarithromycin 125 mg/5 mL suspension twice daily for this 2-year-old child weighing 17 kg. 1
Age-Based Dosing Algorithm
The British Thoracic Society/British Infection Society guidelines provide clear age-based dosing for clarithromycin suspension in children, which takes precedence over weight-based calculations for standard infections:
For children aged 1–2 years: administer 2.5 mL of 125 mg/5 mL suspension twice daily (every 12 hours). 1
This provides 62.5 mg per dose or 125 mg total daily dose for this age group. 1
The dosing frequency is twice daily (bd), meaning every 12 hours. 1, 2
Weight-Based Verification
While the age-based guideline is primary, the weight-based calculation confirms appropriateness:
The recommended pediatric dose is 7.5 mg/kg twice daily (or 15 mg/kg/day total). 2
For a 17 kg child: 7.5 mg/kg × 17 kg = 127.5 mg per dose, which rounds to the standard 2.5 mL dose (62.5 mg) for practical administration in this age bracket. 1
The maximum daily dose should not exceed 1 gram per day regardless of weight-based calculation. 2
Critical Dosing Considerations
Verify the suspension concentration before dispensing. The 125 mg/5 mL formulation is specifically indicated for younger children, while a 250 mg/5 mL formulation exists for older children. 1
Administer doses every 12 hours to maintain therapeutic concentrations throughout the dosing interval. 2
Food does not affect absorption of clarithromycin, so it may be given with or without meals. 3
When to Consider Dose Adjustment
In severe renal impairment (CrCl <30 mL/min), reduce the dose by 50% while maintaining twice-daily frequency. 2
For infants under 1 month, clarithromycin should not be given due to unknown association with infantile hypertrophic pyloric stenosis. 2
Expected Treatment Duration
Typical treatment duration is 7–10 days for most respiratory tract infections in children. 2
For pertussis, treat for 7 days with clarithromycin. 2
For Mycobacterium avium complex (MAC) in children, use 7.5 mg/kg twice daily (maximum 500 mg per dose) for prolonged therapy. 2
Common Pitfalls to Avoid
Do not exceed 1 gram total daily dose in children, even if weight-based calculations suggest higher doses. 2
Do not confuse the 125 mg/5 mL suspension with the 250 mg/5 mL formulation, as this would result in double-dosing. 1
Gastrointestinal symptoms (metallic taste, nausea, vomiting) are dose-related and most common adverse effects, but rarely require discontinuation. 2