Efficacy and tolerability of high-dose cefalexin 45 mg/kg/dose (maximum 1.5 g) three times daily in children with bone and joint infections.

Abstract

Cefalexin, a first-generation cephalosporin, is commonly used as oral continuation therapy for paediatric bone and joint infections (BJIs). The standard four times daily cefalexin dose makes treatment adherence challenging. A pharmacokinetic modelling study found that a cefalexin dose of 45 mg/kg (maximum 1.5 g) three times daily achieves the same pharmacodynamic target. To evaluate the efficacy and tolerability of three times daily cefalexin dosing in children with BJIs. Retrospective audit of children aged 1-18 years who received cefalexin at a dose of 40-50 mg/kg (maximum 1.5 g) three times daily as oral continuation therapy for a haematogenous BJI at a quaternary paediatric hospital in Australia over a 4 year period (January 2019 to December 2022). Of 149 children with BJIs treated with three times daily cefalexin dosing, the majority (147/149; 99%) achieved cure, with two experiencing recurrence of their infection. Most children tolerated the higher cefalexin dose; 4 children experienced gastrointestinal symptoms and 13 developed neutropenia, which was mild in most cases with no associated complications. A reduced frequency dosing regimen using a high cefalexin dose of 45 mg/kg (maximum 1.5 g) three times daily is effective and well tolerated in most children with BJIs.