Pediatric Cephalexin Dosing for Open Fractures
For pediatric open fractures, cephalexin is NOT the appropriate antibiotic choice—cefazolin is the preferred agent for prophylaxis and should be administered intravenously at 33 mg/kg/dose every 8 hours. 1
Why Cephalexin is Inappropriate for Open Fractures
Cephalexin is an oral first-generation cephalosporin that lacks the pharmacokinetic properties needed for acute open fracture management, which requires immediate intravenous antibiotic administration. 1, 2
Critical Distinctions Between Cephalexin and Cefazolin
Route of administration: Cephalexin is oral only and requires absorption from the upper intestine, delaying therapeutic levels 3. Open fractures demand immediate IV antibiotics, ideally within 1 hour of injury 1
Tissue penetration: While cephalexin provides adequate coverage for skin and soft tissue infections at 25-50 mg/kg/day divided doses 2, open fractures require the superior bone penetration and immediate high serum levels achieved with IV cefazolin 1
Clinical evidence: Studies specifically examining open fracture management utilize cefazolin or ceftriaxone, not cephalexin 4. The IDSA recommends cefazolin as the preferred agent for open fracture prophylaxis 1
Correct Antibiotic Management for Pediatric Open Fractures
Cefazolin 33 mg/kg/dose IV every 8 hours is the evidence-based recommendation, with the first dose administered as soon as possible after injury. 1
Dosing Parameters
Maximum daily dose: 150 mg/kg/day divided into three doses (every 8 hours), with no absolute maximum in milligrams 1
Duration: Short-course therapy is appropriate; antibiotics should not extend beyond 24-48 hours post-closure for uncomplicated open fractures 1
Fracture grade considerations: For mild to moderate open fractures (Gustilo-Anderson grades 1-2), cefazolin monotherapy is appropriate 1. Grade 3 fractures may require broader coverage 4
Alternative IV Cephalosporin Option
Ceftriaxone offers equivalent efficacy with the advantage of once-daily dosing (24-hour intervals) and single-agent coverage for grade 3 open fractures. 4 This provides resource efficiency without increasing infectious complications 4
When Cephalexin Might Be Considered
Cephalexin could only be appropriate as oral step-down therapy after initial IV antibiotics and surgical debridement, NOT as initial management. 2, 5
For Seymour fractures (distal phalanx juxta-epiphyseal fractures in children), cephalexin has been used successfully after emergency department management at standard pediatric dosing of 25-50 mg/kg/day divided every 6-12 hours 2, 5
This represents a specific clinical scenario where the fracture has been reduced and the wound managed, allowing transition to oral antibiotics 5
Common Pitfalls to Avoid
Never use oral antibiotics as initial therapy for open fractures—this delays adequate tissue levels and increases infection risk 1
Do not confuse cephalexin (oral) with cefazolin (IV)—they are different drugs despite both being first-generation cephalosporins 1, 2
Avoid extending antibiotic prophylaxis beyond 24-48 hours post-closure unless there are specific indications, as this does not improve outcomes and promotes resistance 1