Calcium channel blockers for lung function improvement in asthma: A systematic review and meta-analysis.

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.