Use of gentamicin serum levels to individualize therapy in children

The value of a one-compartment pharmacokinetic model for calculating gentamicin half-life and predicting steady-state serum concentrations was assessed in 20 children, 32 to 168 months of age, who were receiving the drug intravenously for gram-negative bacterial infections. Actual steady-state serum concentrations measured after the twenty-fourth or twenty-fifth doses were compared with corresponding values predicted by the model. The mean predicted steady-state serum concentration at 30 minutes after the intravenous dose, 3.6 μg/ml, was 13% less than the mean measured value, 4.15 μg/ml. The mean predicted steady-state nadir serum concentration was 0.152 μg/ml, or 54% less than the mean measured value, 0.33 μg/ml. The mean t 1/2 for decline in serum concentrations following the first dose was 66.9 minutes, which was significantly different ( P