OBJECTIVES: Prior authorization (PA), the requirement of physicians to obtain pre-approval as a prerequisite for coverage may decrease drug utilization via a “sentinel effect”, a decrease in utilization caused by external review of prescribing. The purpose of this study was to assess the affect a PA restriction had on the utilization patterns of cefuroxime tablets in a Managed Care Organization (MCO) in Israel. METHODS: Prescribing patterns were evaluated from electronic patient records. A retrospective drug-utilization analysis was conducted. All prescriptions for solid state antibiotics for patients diagnosed with an infectious disease during three parallel, three month segments: before, during, and after a PA restriction for cefuroxime was enforced were included. Frequency and proportion of antibiotic prescriptions for cefuroxime, distribution of infectious diseases treated with cefuroxime, and the request rejection rate when PA was required were calculated. RESULTS: Prescription of cefuroxime declined from 5538 (8.0% of eligible antibiotic prescriptions, 95% CI = 7.8, 8.2) in the initial period to 1036 (1.2%, 95% CI = 1.1, 1.3) during the PA period, rising to 3961 (4.3%, 95% CI = 4.2, 4.4) in the post-PA period. Changes in the distribution of diseases treated with cefuroxime during the PA stage tended to regress after revocation to those observed in the pre-PA period. The rejection rate was 8.5% (95% CI = 6.9-10.1). CONCLUSIONS: Although a PA requirement for cefuroxime markedly reduces utilization probably due to a “sentinel effect”, it will not lead to residual effects on prescribing behavior upon its revocation, indicating the need for a multi-pronged approach in the realm of policy, regulation and management regarding prescribing behavior. While many articles have alluded to the need to create a “culture of quality”, we suggest a multi-pronged approach including focus groups and surveys of physicians, implementation of clinical guidelines, and ongoing feedback in an Israeli MCO.