Cost Analysis of Therapeutic Interchange of Calcium Channel Blockers for the Treatment of Hypertension: Unexpected Results from a Conversion Program

Abstract

An examination of drug expenses and overall health care resource utilization associated with a calcium channel blocker therapeutic interchange and conversion program is reported in 101 patients, mean age 68 yr, receiving extended release nifedipine (Procardia XL) who were converted to either amlodipine besylate (Norvasc) or felodipine (Plendil) through the Veteran Administration's hospital conversion program. Unexpectedly, the total cost of drug therapy was significantly higher during the 9 month postconversion period relative to the 9 month preconversion period. Neither the total number of clinic visits nor the number of hospitalizations differed significantly between the preconversion and postconversion periods. No significant differences in the grade of hypertension was observed from the preconversion period to the postconversion period, although there were statistically significant drops in both systolic and diastolic blood pressures. (8 refs.) (Abstract by Lisa Webster.)