STANDARDIZED GENTAMICIN DOSING ENHANCES PEAK SERUM CONCENTRATIONS

The objectives of this study were to determine if a standardized genta micin dosing protocol would improve clinical effectiveness, yield high er peak serum concentrations, and improve the success rate of attainin g peaks in the desired range when compared with empiric dosing practic es used by prescribers. The study was conducted as a before-after prog ram effectiveness evaluation in non-critically ill patients, aged 16-6 5 y with stable renal function, who were prescribed gentamicin. A stan dardized dose of 2 mg/kg (ideal or adjusted weight) was administered i ntravenously every 12 h in the intervention phase. Response to therapy (time to defervescence, white cell count, reinstitution of antibiotic therapy), serum concentrations (peaks >10 mu mol/L (5.6 mg/L) and tro ughs <4 mu mol/L (2.2 mg/L)), and toxicity were monitored in both grou ps. Thirty-four consecutive patients were enrolled into the control ph ase and an equal number into the intervention phase. Surgical patients comprised the majority of the study population. Desired peak concentr ations were attained in 97% of intervention vs. 59% of control patient s (p < 0.001). Mean peak serum concentrations were higher in the inter vention phase than in the control phase, 16.1 mu mol/L vs. 11.2 mu mol /L (p < 0.001), respectively. Median time to become afebrile trended t oward a statistical decrease in the intervention as compared to the co ntrol group, 3 vs. 5 d (p = 0.076), respectively. There was no signifi cant difference in clinical effectiveness nor in the occurrence of nep hro- or ototoxicity. Continued evaluation of this dosing protocol is w arranted.