Duration of protection of calcium channel blockers against exercise-induced bronchospasm: comparison of oral diltiazem and inhaled gallopamil.

The present study was conducted to determine the duration of the positive effect of oral diltiazem and inhaled gallopamil in mild asthmatic volunteers, ages 18-37 years, with a history of exercise-induced asthma and a 25-56% decrease in FEV1 after a standardized exercise challenge. Oral diltiazem 120 mg, inhaled gallopamil 10 mg, and placebo were administered in a double blind, randomized, crossover manner on different days 48 h apart. Diltiazem was administered 90 min and gallopamil 30 min before the first exercise challenge. Challenges were then repeated 3 and 6 h later. Neither diltiazem nor gallopamil significantly altered baseline FVC, FEV1, or FEF25-75. The mean maximum decrease in FEV1 after the first challenge was 16.8% after gallopamil, 25.2% after diltiazem and 30.1% after placebo. The mean post-exercise decrease in FEV1 after gallopamil was significantly smaller than after placebo. There were no significant differences in the post-exercise decreases in FEV1 between the three treatment regimens 3 and 6 h later. Thus, inhaled gallopamil provided significant protection against exercise-induced bronchospasm, but the beneficial effect was modest and short in duration.

RCT Entities:   Population Interventions Outcomes