IMPACT OF VANCOMYCIN THERAPEUTIC DRUG-MONITORING ON PATIENT-CARE

OBJECTIVE: To document differences in the outcome of vancomycin therap y in patients managed through a therapeutic drug monitoring (TDM) serv ice and patients managed empirically, without the participation of a T DM service. DESIGN: Prospective, cohort study. SETTING: An 1100-bed, t ertiary-care, teaching hospital. PATIENTS: Those who received vancomyc in for more than four days, were at least 18 years old, had an estimat ed creatinine clearance of more than 0.33 mL/s (20 mL/min), were not n eutropenic at the start of vancomycin therapy, and were not treated in a critical care unit were enrolled in the study. A total of 116 patie nts (61 TDM; 55 non-TDM) were monitored prospectively from June 1990 t hrough March 1991. INTERVENTIONS: Patients in the TDM group had vancom ycin drug therapy monitored daily by a pharmacist and vancomycin dosag es adjusted following a pharmacokinetic analysis of vancomycin serum c oncentrations. For patients in the non-TDM group, the pharmacist only completed a data collection form. The patients and physicians were una ware of the monitoring. MAIN OUTCOME MEASURES: Duration Of therapy, to tal vancomycin dosage, infection site, concomitant antibiotics, body t emperature, and white blood cell counts were compared between the two groups. Length of stay data were also compared. Nephrotoxicity was eva luated by comparing serum creatinine concentration and estimated creat inine clearance. RESULTS: TDM of vancomycin appeared to reduce the inc idence of vancomycin-related renal insufficiency (TDM 7 percent; non-T DM 24 percent). Patients managed through the TDM service received an a verage of 5 g less of vancomycin than did the patients in the non-TDM group. The duration of vancomycin therapy was an average of 2 days les s for patients in the TDM group. Mean length of stay was 38.0 days for the TDM group and 44.5 days for the non-TDM group. Other measures of efficacy, infection site, and concomitant antibiotics were the same fo r both groups. CONCLUSIONS: TDM of vancomycin was associated with fewe r cases of vancomycin-related renal insufficiency. Vancomycin efficacy was not compromised by TDM. Provision of TDM for vancomycin therapy a ided in patient management.