Ondansetron use in a major university teaching hospital

A drug-use evaluation of ondansetron was conducted. Literature-based criteria for the use of ondansetron were developed by an oncology specialty resident and a clinical pharmacy specialist in oncology. Orders for ondansetron written in the hospital or in the outpatient oncology clinic were reviewed over a nine-week period. After an interval of education, the use of ondansetron was re-evaluated. The data collected included the indication for use, dosage, route of administration, and, for inpatient orders during the first evaluation, therapeutic outcome. In the first evaluation, 100 orders were reviewed. Some 87% of the orders for inpatients and 80% of the outpatient orders met the criteria for therapeutic indication. Criteria for dosage and administration were met by 76% of the inpatient orders and 83% of the outpatient orders. The inpatient orders met the criteria for therapeutic outcome in 93% of cases. In the follow-up evaluation, 50 orders were reviewed. Some 96% of the inpatient orders and 100% of the outpatient orders met the criteria for therapeutic indication. Dosage and administration criteria were met by 92% of the inpatient orders but only 24% of the outpatient orders. A considerable potential for cost avoidance was identified. An evaluation of ondansetron use led to general improvements in prescribing patterns, but continued monitoring is necessary to reduce the use of inappropriate dosages and routes of administration for outpatients.