Evaluation of a computer-assisted antibiotic-dose monitor

OBJECTIVE: To examine the effect of a computer-assisted antibiotic-dose monitor used to reduce the number of days that patients receive excessive dosages of antibiotics and the number of adverse drug events (ADEs) secondary to antibiotics. DESIGN: Descriptive epidemiologic study of a two-year preintervention period and one-year intervention period. SETTING: The LDS Hospital, a tertiary care center in Salt Lake City, UT. PATIENTS: All patients aged > or = 18 years, admitted to LDS Hospital from April 1, 1993, to March 31, 1996, who received at least one of five targeted antibiotics (vancomycin, gentamicin, imipenem, cefazolin, cefuroxime), who had a serum creatinine or a urine creatinine clearance test result before antibiotic therapy, and who were never admitted or transferred to the shock/trauma/respiratory intensive care unit. METHODS: Each morning during the 12-month intervention period, the antibiotic-dose monitor checked the renal function of all patients who were receiving any of the five antibiotics. Pharmacists received a computer listing of patients who may have been receiving excessive dosages. The antibiotic-dose monitor suggested an alternate dosage and a pharmacist contacted the patient's physician if the suggested change in the dosage was appropriate. RESULTS: During the intervention period, 4483 patients received at least one of the five study antibiotics and 1974 (44%) were identified as receiving an excessive dosage, compared with 4494 (50%) of 8901 patients during the preintervention period (p < 0.001). The patients receiving excessive dosages received an excessive dosage for an average of 2.9 days during the intervention period, compared with 4.7 days (p < 0.001) during the preintervention period. In addition, these same patients during the intervention period received fewer doses of antibiotics (10.9 vs. 13.4; p < 0.001), fewer grams of antibiotics (10.4 vs. 12.0; p < 0.02), at less cost ($98 vs. $128; p < 0.004) than the patients during the preintervention period. Moreover, there were 14 ADEs (0.3%) secondary to the five study antibiotics during the intervention period, compared with 82 (0.9%; p < 0.001) for the two-year preintervention period. The study also found that significantly more patients identified as receiving excessive dosages had experienced decreases in renal function, compared with patients who were not identified as receiving excessive dosages (25% vs. 12% during preintervention period and 23% vs. 16% during intervention period; p < 0.001). CONCLUSIONS: Many patients experience decreases in renal function after antibiotics are ordered. The use of the computer-assisted antibiotic-dose monitor appears to be a promising method to help reduce the excessive use and cost of antibiotic therapy and reduce the number of ADEs secondary to antibiotics.