Therapeutic drug monitoring of gentamicin in patients with bronchopneumonia: cost considerations and patient outcomes.

OBJECTIVE In Malaysia, therapeutic drug monitoring (TDM) service started in the late 1980s. Serum concentration measurements depend on commercially available drug assays, which are costly. In the present study, we attempted to document the impact of TDM service on cost and patient outcomes. MATERIALS AND METHODS We reviewed the medical records of the patients who were admitted to the hospital over a five-year period, diagnosed with bronchopneumonia and treated with gentamicin. Outcome measures were duration of fever, incidence of nephrotoxicity and length of hospital stay. We calculated the costs of laboratory and clinical investigations, the costs associated with the administration of gentamicin doses, the cost of providing TDM services, the costs associated with medical care by professional staff and the costs of hospital stays during gentamicin treatment. RESULTS Sixty-six patients were found to meet the inclusion criteria (10 patients were provided with TDM service and 56 patients were not). There was no significant difference in the duration of fever or the length of hospital stay during gentamicin therapy between the two groups. Although serum creatinine levels were not checked in all of the patients after gentamicin therapy, the data analysis did not show any cases of nephrotoxicity. There was no significant difference in the costs of laboratory investigations, the total cost of gentamicin therapy and the costs associated with professional staff between the two groups. The cost of the hospital stay during gentamicin therapy and the total cost of hospitalization were significantly higher in the TDM group. CONCLUSION Evaluation in patients with bronchopneumonia shows that TDM in our setting was associated with higher cost; however, we did not observe any significant differences in the clinical outcomes.