What is the recommended dose of Keflex (Cephalexin) for a pediatric patient with a hordeolum (stye)?

Dosing of Cephalexin for Pediatric Stye (Hordeolum)

For pediatric patients with a hordeolum (stye), cephalexin should be dosed at 25-50 mg/kg/day divided into 4 doses (every 6 hours) for 7 days. 1, 2

Dosing Recommendations

• The FDA-approved dosage for cephalexin in pediatric patients is 25-50 mg/kg/day divided into 4 doses 1
• For skin and skin structure infections (including styes), the total daily dose may be divided and administered every 12 hours (twice daily) in some cases 1
• The usual duration of therapy for skin infections is approximately 7 days, depending on clinical response 2

Weight-Based Dosing Guide

For cephalexin suspension:

• 10 kg (22 lb): 1/2 to 1 tsp (125 mg/5 mL) four times daily or 1/4 to 1/2 tsp (250 mg/5 mL) four times daily 1
• 20 kg (44 lb): 1 to 2 tsp (125 mg/5 mL) four times daily or 1/2 to 1 tsp (250 mg/5 mL) four times daily 1
• 40 kg (88 lb): 2 to 4 tsp (125 mg/5 mL) four times daily or 1 to 2 tsp (250 mg/5 mL) four times daily 1

Alternative Dosing Schedules

• Recent research suggests that less frequent dosing may be acceptable to improve adherence:
  • For twice-daily dosing: 22-45 mg/kg per dose (for MSSA with MICs of 1-2 mg/L) 3
  • For three-times-daily dosing: 15-25 mg/kg per dose (for MSSA with MICs of 1-2 mg/L) 3
  • These alternative regimens may improve treatment compliance while maintaining efficacy 3

Clinical Considerations

• Styes are typically caused by Staphylococcus aureus, most commonly methicillin-susceptible S. aureus (MSSA) 2
• Cephalexin is effective against MSSA and is an appropriate first-line oral agent for skin and soft tissue infections caused by this organism 2
• For penicillin-allergic patients (except those with immediate hypersensitivity reactions), cephalexin remains a suitable option 2
• For patients with immediate hypersensitivity to penicillin, clindamycin (10-20 mg/kg/day in 3 divided doses) may be considered as an alternative 2

Important Caveats

• If there is concern for methicillin-resistant S. aureus (MRSA), alternative antibiotics such as clindamycin or trimethoprim-sulfamethoxazole should be considered 2
• Tetracyclines should not be used in children under 8 years of age 2
• For severe infections or those not responding to initial therapy, cultures should be obtained to guide antibiotic selection 2
• After mixing cephalexin suspension, store in refrigerator; may be kept for 14 days without significant loss of potency 1

Supportive Measures

• Warm compresses applied to the affected eye several times daily can help promote drainage 2
• Maintain good personal hygiene with regular hand washing to prevent spread of infection 2
• Keep the affected area clean and avoid touching or squeezing the stye 2