Differences in alpha blocker usage among enlarged prostate patients receiving combination therapy with 5 ARIs

The objective of this study was to directly assess the likelihood and timing of alpha blocker discontinuation in patients receiving combination therapy with dutasteride or finasteride plus an alpha blocker.

A retrospective analysis of the PharMetrics Integrated Medical and Pharmaceutical Database (Watertown, Mass) was conducted to assess differences in alpha blocker discontinuation rates for patients initiated on 5-alpha reductase inhibitor (5ARI) therapy. The database is nationally representative, encompassing more than 45 million patients from 85 managed healthcare plans. Male patients aged >50 years with a diagnosis of enlarged prostate (EP) who were receiving alpha blocker therapy and who began 5ARI treatment (dutasteride or finasteride) between January 1, 1999, and March 1, 2005, were included. Patients were studied for up to 12 months to evaluate the likelihood and timing of alpha blocker discontinuation.

Overall, 56.7% of the patients remained on alpha blocker therapy for 6 months. At 1 year, more dutasteride patients had discontinued alpha blocker therapy (48.9% remained on alpha blocker) than finasteride patients (58.7% remained on alpha blocker). After controlling for background covariates, dutasteride patients were 19.9% more likely to discontinue alpha blocker therapy over 365 days.

Patients with EP who are taking an alpha blocker and 5ARI in combination for urinary symptom relief discontinue their alpha blocker 19.9% earlier when taking dutasteride than when taking finasteride. The ability to discontinue alpha blocker therapy earlier could reduce the costs of pharmacotherapy while continuing to provide an adequate level of symptom control and disease modification, which may result in cost savings to healthcare plans.