RESUMO
OBJECTIVE: Managed care organizations can increase the value of drug therapy by negotiating discounts on drug acquisition costs with pharmaceutical manufacturers and promoting use of preferred drugs, including the conversion of patients to preferred medications. This investigation was designed to assess conversion success, migraine drug utilizations, and patient satisfaction with a clinical pharmacist-managed conversion program from sumatriptan to rizatriptan ODT, both formulary drugs. METHODS: This was a retrospective cohort study conducted in a managed care organization for patients aged 18 years or older who had picked up at least one outpatient prescription for any sumatriptan dosage form at the pharmacy between January 2002 and June 2002. Patients. pharmacy and medical data were reviewed to assess eligibility (e.g., no history of rizatriptan failure) for conversion from sumatriptan to rizatriptan orally disintegrating tablet (ODT). There was no copayment difference for members for rizatriptan ODT versus sumatriptan. A questionnaire was developed to assess 2 domains: (1) patient satisfaction with the medication conversion process and (2) preference for rizatriptan ODT or sumatriptan. A random sample of 315 patients who initiated conversion to rizatriptan ODT was surveyed. Electronic pharmacy claims were reviewed to determine the number of patients who were successfully converted from sumatriptan to rizatriptan ODT. Pharmacy expenditures and total health care utilization and expenditures in the 180 days prior to (baseline) and after the conversion (followup) to rizatriptan ODT were compared for the cohorts of subjects who were successfully converted and those patients who were not successfully converted. RESULTS: Therapeutic conversion from sumatriptan to rizatriptan ODT was attempted in 457 patients; 214 (47%) were successfully converted. The only difference between the 2 cohorts at baseline for the 6 months prior to attempted conversion was a higher mean number of sumatriptan doses per patient per month (PPPM) in the 243 failed conversions (mean 3.5, SD 2.9) compared with the 214 successful conversions (mean 2.8, SD 2.8, P =0.003). The median triptan doses increased by 1.0 PPPM in both cohorts (P =0.882), from 2.0 to 3.0 doses PPPM in the group of successful conversions and from 2.7 to 4.0 in the group of unsuccessful conversions. The survey response rate was 55% for both successful and for unsuccessful conversions. More than 90% of the patients in both cohorts were satisfied with the level of care provided by the clinical pharmacy staff during medication conversion, and there was no difference between the 2 cohorts in patient satisfaction (P=0.761). Rizatriptan ODT was preferred by 68.0% and 8.5% of successful and failed conversion subjects, respectively (P <0.001). Using representative group purchase prices, triptan expenditures for successful conversion subjects were reduced by a median of -2 dollars (6 %) PPPM while triptan expenditures for unsuccessful conversions increased by a median of 8 dollars (P <0.001). There were no differences for either cohort in median PPPM changes in migraine-related office visits (0.0 median change in office visits, P =0.748) or office-visit costs (0 dollars median change, P =0.861) for preconversion versus postconversion attempts Regression modeling identified that lower total counts of sumatriptan doses filled during baseline period was an independent predictor of successful conversion to rizatriptan ODT (P <0.001). There was an average of 3.5 triptan medication fills per patient for successful conversion during the 6-month follow-up period, with 78% of these subjects filling at least 2 prescriptions for rizatriptan ODT during this period. CONCLUSIONS: This conversion program for sumatriptan to rizatriptan ODT was successful in converting almost half of primary care patients to the preferred product despite the absence of a copayment incentive for members to agree to the conversion. There were no measurable medical or economic consequences of the conversion, and patient satisfaction with the quality of care was maintained. Future efforts are likely to have a higher success rate if focused on converting patients with less-severe migraine headaches, as measured by the need for baseline rescue medication, since lower acuity was the only independent predictor of successful conversion in this conversion program for 2 triptan drugs.