What is the suitable dose of clindamycin for a 28 kg child if administered twice daily?

Clindamycin Dosing for a 28 kg Child on Twice Daily Administration

For a 28 kg child requiring twice daily clindamycin administration, the appropriate dose is 10-13 mg/kg/dose given every 12 hours, which equals 280-364 mg per dose twice daily. 1

Dosing Calculation and Rationale

The FDA-approved dosing for clindamycin in pediatric patients with serious infections is 8-16 mg/kg/day divided into three or four equal doses, and for more severe infections, 16-20 mg/kg/day divided into three or four equal doses 1. However, when administering twice daily instead of the standard three to four times daily:

• Standard pediatric dosing: 8-20 mg/kg/day divided into 3-4 doses
• When converting to twice daily dosing:
  • Total daily dose remains the same: 8-20 mg/kg/day
  • For a 28 kg child: 224-560 mg total daily dose
  • Divided into two doses: 112-280 mg per dose (for standard infections)
  • For more severe infections: up to 280 mg per dose twice daily

Important Clinical Considerations

1. Infection Severity Matters

   • For serious MRSA infections, the Infectious Diseases Society of America recommends clindamycin 10-13 mg/kg/dose IV every 6-8 hours (to administer 40 mg/kg/day) 2
   • When converting this to twice daily dosing, each dose would need to be higher to maintain the same daily exposure

2. Potential Risks of Twice Daily Dosing

   • Less frequent dosing may result in higher peak concentrations and lower trough concentrations
   • This could potentially impact efficacy for certain infections
   • The FDA label specifically recommends three to four equal doses 1

3. Safety Considerations

   • Monitor for gastrointestinal side effects, particularly diarrhea
   • If significant diarrhea occurs, discontinue therapy due to risk of C. difficile infection 1
   • Administer with a full glass of water to avoid esophageal irritation

Practical Administration

• For a 28 kg child:
  • Lower range (10 mg/kg/dose): 280 mg twice daily
  • Higher range (13 mg/kg/dose): 364 mg twice daily
  • Available capsule strengths: 75 mg, 150 mg, 300 mg
  • Practical dosing: 300 mg twice daily (closest available capsule strength)

Important Caveats

• Twice daily dosing is not the standard FDA-approved regimen for clindamycin 1
• For serious infections, particularly MRSA infections, the standard recommendation is dosing every 6-8 hours 2
• If the child cannot swallow capsules whole, the oral solution formulation should be used instead 1
• For β-hemolytic streptococcal infections, treatment should continue for at least 10 days 1

Monitoring

• Assess clinical response within 48-72 hours
• Monitor for diarrhea or other gastrointestinal symptoms
• Ensure the child takes the medication with a full glass of water

While twice daily dosing may improve adherence in this case where the mother refuses more frequent administration, it represents a compromise between optimal pharmacokinetics and practical considerations for medication adherence.