The Rational Use of Antibiotics: The Princess Margaret Hospital Experience

In the past decade, there has been an alarming trend towards increased antimicrobial resistance in many human pathogens. Of the many possible factors responsible for these developments, the overuse and inappropriate prescribing of broad-spectrum antibiotics has been implicated (1). Rational, cost effective drug use needs to be promoted to begin controlling this problem. A structured drug use evaluation (DUE) process involving clinical pharmacists, staff physicians and infectious disease (ID) specialists has been reported to be effective in promoting appropriate drug prescribing (2). During the past 20 years, hospital-based retrospective and prospective DUE studies have played an integral role in health care delivery. Retrospective DUE involves an analysis of drug use after therapy has been administered. Prospective studies usually begin with the development of guidelines for the appropriate use of the agent in question (2,3). A formal evaluation process is initiated where pharmacists monitor drug therapy over a specified period of time. Interventions necessary to correct inappropriate prescribing patterns are then implemented before therapy is administered. The results of such studies are usually presented as the proportion of drug orders meeting guidelines following the intervention. The primary objective of many DUE studies is to improve physician prescribing within a set of hospital-approved guidelines for drug use. Theoretically, this should reduce the annual usage of broad-spectrum antimicrobials, thereby limiting the development of antimicrobial resistance. The DUE approach has demonstrated its ability to alter physician prescribing patterns in several drug classes, such as antiemetics, H2-receptor antagonists and antimicrobials (4-6). In one report, Lazor-Bajcar and Fowler (7) conducted a prospective DUE on the use of intravenous metronidazole in a community hospital. In that study, an initial retrospective audit of metronidazole determined that approximately 50% of all prescriptions did not meet hospital guidelines. A pharmacist-driven intervention program was initiated for all orders outside of the guidelines. Subsequent drug use within hospital guidelines increased to 86%, and there was an annual reduction in intravenous metronidazole usage by approximately 70% (7).