Outcome of patients treated by an aminoglycoside pharmacokinetic dosing service.

Differences in outcome between patients whose aminoglycoside dosing regimens were individualized by a clinical pharmacokinetic dosing service (CPDS) and patients who did not receive CPDS consultation were evaluated by retrospective chart review. Data for a number of dependent variables that might affect patient outcome were collected from the medical records of 42 patients with culture-proven gram-negative pneumonia or sepsis who had received CPDS dosing consultations and 60 similar patients who had not received CPDS consultations. Data were also collected for a number of analytical and categorical independent variables to evaluate sources of variation between the groups. Variables were compared using both parametric and nonparametric statistical tests. For patients whose dosing regimens had been individualized by the CPDS, length of aminoglycoside therapy and length of stay were significantly shorter, changes in serum creatinine concentration from baseline were significantly smaller, and mortality was significantly lower; morbidity was reduced by significantly fewer incidences of aminoglycoside nephrotoxicity. Significant differences existed between the mean dosing intervals, mean numbers of serum aminoglycoside concentration determinations, and mean baseline serum creatinine concentrations for the two groups. Although a favorable difference in patient outcome was demonstrated for patients whose dosing regimens were individualized by the CPDS, unmeasurable differences between the two groups of patients make it difficult to attribute the difference solely to the effect of the dosing service.