Objective: The objective of this study was to characterize gentamicin population pharmacokinetics (PKs) in Indian pediatric patients.Methods: Population PK analysis was performed with nonlinear mixed-effect model software. The data set was inspected using both first order (FO)and FO conditional estimate (FOCE) methods by the inclusion of both patient and pathological conditions.Results: A total of 26 patients were involved in this study with 54 observations. The patient covariates, including body weight, gender, age, andcreatinine clearance (CLCR), were analyzed in a stepwise fashion to identify their potential influences on gentamicin PKs. The final modelgives the clearance (CL) and volume of distribution (V) by FO method as CL=θ1*(CLCR/35.14)+θ3*(WT/14.25)+θ5*(AGE/6.14)*EXP(θ1),V=θ2*(WT/14.25)+θ4*(CLCR/35.14)+θ6*(AGE/6.14)*EXP(θ2) and by FOCE method as CL=θ1*(CLCR/35.14+)θ3*(AGE/6.14)*EXP(θ1),V=θ2*(WT/14.25)+θ4*(CLCR/35.14)+θ6*(AGE/6.14)*EXP(θ2).Conclusion: The final model estimates of CL and V were 0.0014 L/hr/kg and 0.646 L/kg, respectively, and by FOCE method were 0.0014E-06 L/hr/kgand 0.774 L/kg, respectively. These parameters will be helpful in individualizing the loading and maintenance doses in pediatric patients.Keywords: Population pharmacokinetics, Gentamicin, Nonlinear mixed-effect model, Pediatrics
