OBJECTIVES: To assess the effect of prior authorization (PA) on the appropriate gastrointestinal (GI) prescribing of tegaserod in a managed care population. METHODS: Retrospective analysis was conducted of pharmacy and medical claims data of tegaserod users from four geographically diverse managed care health plans. Members who were continuously enrolled and initiated on tegaserod therapy between August 1, 2002 and December 31, 2003 were included in the study. The first prescription fill date for tegaserod during this period was considered the index prescription date. Index diagnosis visit was defined as the closest physician visit with a GI-related diagnosis either before or after the index prescription date. Diagnostic characteristics were evaluated during a 2-year period (1 year before and 1 year after the index prescription date). Appropriate GI prescribing of tegaserod, defined as a claim for IBS or at least one of its symptoms—abdominal pain, bloating, or constipation—was assessed for plans with and without PA. RESULTS: In total, 2638 tegaserod users had an index diagnosis visit for a GI-related disorder; 93.5% were female, and the mean age was 48.6 (SD=13.7) years. During the 24-month observation period, 93.6% of the patients were appropriately prescribed tegaserod. Specifically, they were diagnosed with IBS (56.4%), constipation (21.2%), abdominal pain (15.8%), or bloating (1.3%). There were no differences in the appropriate prescribing of tegaserod in patients whose plan required PA (n=998) compared with patients whose plans did not require PA (n=1640) (94.1% vs 93.4%, respectively, p=0.45). CONCLUSION: Most patients receiving tegaserod had a diagnostic claim for IBS or one of its cardinal symptoms (abdominal pain, bloating, or constipation), indicating that tegaserod is being prescribed appropriately. Moreover, our analysis revealed that PA for tegaserod did not have an effect on appropriate GI prescribing, thus bringing into question the value of PA.