THE COSTS AND EFFECTS OF SWITCHING CALCIUM-CHANNEL BLOCKERS - EVIDENCE FROM MEDICAID CLAIMS DATA

This study used Medicaid claims data from Pennsylvania to examine the costs and effects of changing calcium channel blocker therapies. Speci fically, we compared Procardia XL(R) with Adalat(R) CC. They are the o nly once-daily-dosed, extended-release forms of nifedipine available. These drugs were interesting to compare for several reasons. First, be cause the frequency of treatment regimens has been shown to be the mos t important determinant of long-term compliance with calcium channel b locker medications, it was desirable to compare drugs having identical dosing regimens. Second, switching from one to the other should be qu ite feasible in most patients. Third, Adalat CC is priced (ie, average wholesale price) less than Procardia XL. The results indicate that pr escription prices were lower when patients were switched from Procardi a XL to Adalat CC, with no apparent effects on blood pressure control, the incidence of adverse drug reactions, or nonprescription health ca re costs. The potential savings to Medicaid from switching patients fr om Procardia XL to Adalat CC appears to be large, more than $2.5 milli on annually for Procardia XL-treated Medicaid patients in the state of Pennsylvania. Our study also demonstrates that large retrospective da tabases can be used to evaluate economic and clinical outcomes for spe cific therapy alternatives. Such evaluations are increasingly relevant to third-party payers, health maintenance organizations, and other pa rties involved in managed care.