Recommended Dosage of Cephalexin for Pediatric Patients
The recommended dosage of cephalexin for pediatric patients is 25-50 mg/kg/day divided into 3-4 doses, with a specific dosage of 75-100 mg/kg/day in 3-4 divided doses for methicillin-susceptible Staphylococcus aureus infections. 1, 2
Standard Dosing Recommendations
- The FDA-approved dosage for cephalexin in pediatric patients is 25-50 mg/kg/day divided into 3-4 doses 1
- For more severe infections, the dosage may be doubled 1
- For methicillin-susceptible Staphylococcus aureus (MSSA) infections, the recommended oral dosage is 75-100 mg/kg/day divided into 3-4 doses 2
- For streptococcal pharyngitis in patients over 1 year of age and for skin and skin structure infections, the total daily dose may be divided and administered every 12 hours 1
Specific Clinical Scenarios
- For otitis media, clinical studies have shown that a higher dosage of 75-100 mg/kg/day in 4 divided doses is required 1
- For treatment of β-hemolytic streptococcal infections, cephalexin should be administered for at least 10 days 1
- For bone and joint infections, recent research supports using 45 mg/kg/dose (maximum 1.5 g) three times daily as an effective and well-tolerated regimen 3
Alternative Dosing Schedules
- Recent pharmacokinetic studies support less frequent dosing regimens that may improve treatment adherence while maintaining efficacy 4:
Pharmacokinetic Considerations
- Cephalexin is rapidly absorbed in the upper intestine and distributed to tissues 5
- Children may require higher doses per kilogram than adults due to their greater body water turnover 5
- Cephalexin is rapidly cleared by the kidneys with 70-100% of the dose found in urine 6-8 hours after administration 5
Common Pitfalls and Caveats
- Dose adjustment is necessary for patients with renal impairment (creatinine clearance <30 mL/min) 5
- If daily doses greater than 4 g are required, parenteral cephalosporins should be considered 1
- Gastrointestinal symptoms and mild neutropenia may occur with higher doses but are generally well-tolerated 3
- After mixing the suspension, it should be stored in the refrigerator and may be kept for 14 days without significant loss of potency 1