title: Kinetic model for gentamicin dosing with the use of individual patient parameters.
abstract: Multiple-infusion dosing regimens for gentamicin were established for 84 patients with the use of individually calculated values of elimination kinetic parameters. Serum level-time data obtained after a single infusion were used to determine the patient's gentamicin half-life (t 1/2) and distribution volume. Patients with serum creatinine (Cr) less than 1.2 mg per 100 ml had t 1/2 (mean, 2.25 hr) and total body clearances (mean, 0.082 L/hr/kg) significantly different from those with Cr greater than or equal to 1.2 mg/100 ml (means, 5.3 and 0.039, respectively). Distribution volumes were not significantly different (means, 0.22 and 0.21 L/kg, respectively). Calculations of dosing intervals and infusion rates, based on each patient's kinetic parameters and desired steady-state peaks and nadirs, assumed a one-compartment model with first-order elimination and 1-hr constant-rate input at fixed intervals. Follow-up steady-state peak and nadir levels were measured in 63 of the regimens. Differences between predicted and measured peak levels averaged --0.05 mug/ml with 60% of the measured values falling within 1 mug/ml of that predicted. Predicted-measured nadir differences averaged --0.62 mug/ml (significantly different from zero) indicating slight bias in the model. Fifty-six percent of these nadirs were within 1 mug/ml of that predicted.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000378:metabolism; D004334:Drug Administration Schedule; D005839:Gentamicins / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism; D006207:Half-Life; D006801:Humans; D007223:Infant; D007263:Infusions, Parenteral; D007700:Kinetics; D008875:Middle Aged
chemical_list: D005839:Gentamicins; D003404:Creatinine