Gentamicin and Tobramycin Pharmacokinetics in Pediatric Bone Marrow Transplant Patients

OBJECTIVE:To describe the pharmacokinetic parameters of gentamicin and tobramycin in pediatric bone marrow transplant patients.DESIGN:Retrospective medical record review.Setting: Pediatric bone marrow transplant unit in a university teaching hospital.MAIN OUTCOME MEASURES:Pharmacokinetic parameters (apparent volume of distribution [Vd] in L/kg, half-life [t1/2] in h, elimination rate constant [ke] in h−1, clearance [Cl] in mL/min/1.73 m2 and mL/min/kg) calculated from serum concentrations.PATIENTS:Thirty-three patients aged 15 years or less who underwent bone marrow transplant and received gentamicin or tobramycin.RESULTS:Mean pharmacokinetic parameters were Vd 0.32 ± 0.07 L/kg, t1/2 2.32 ± 0.65 h, Cl 1.71 ± 0.53 mL/min/kg, and Cl 86.2 ± 24.5 mL/min/1.73 m2. Factors such as disease state, type of marrow graft, gender, or exposure to cyclosporine had no significant effect on pharmacokinetic parameters. Linear regression indicated a weak relationship between serum creatinine (SCr) and Cl in mL/min/kg (r = 0...