Abstract
BACKGROUND For decades, calcium channel blockers (CCBs) have been believed to play a role in asthma treatment. However, the clinical efficacy of CCBs for lung function improvement in patients with asthma has not been qualitatively evaluated. OBJECTIVE To assess the effect of CCBs vs placebo on lung function test results in adults with asthma. METHODS Various databases were systematically searched to identify all randomized clinical trials with adults with asthma. We aimed to assess the influence of CCBs on forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), peak expiratory flow rate (PEFR), and provocative concentration of bronchoconstrictive agents causing a 20% decrease in FEV1 (PC20) compared with a placebo. All effect estimates were pooled by the generic inverse variance method with random-effects meta-analysis. Subgroup analysis, sensitivity analysis, and heterogeneity investigation were performed. RESULTS Thirty eligible articles with 301 patients were included in this meta-analysis. Our results revealed that in a standard exercise test CCBs could produce a mean maximal percentage decrease in FEV1 of 11.56% (95% confidence interval, 8.97%-14.16%; P < .001) and an increase in postdose FEV1 by 80 mL (95% confidence interval, 0.02-0.15 mL; P = .01). However, there was no statistical significance for CCBs in postdose FVC, PEFR, or PC20 of histamine and methacholine. CONCLUSION CCBs may be beneficial for lung function improvement in asthma, especially in exercise-induced asthma. However, there is a lack of evidence for CCBs protecting asthma patients from chemical irritation.
