Safety of nifedipine in subjects with bronchial asthma and COPD.

This prospective study was undertaken to evaluate the safety of nifedipine, a calcium channel blocking agent, on 60 subjects with asthma, chronic obstructive pulmonary disease (COPD), angina, and normal subjects. All subjects received nifedipine, 20 mg, sublingually. Spirometry was done pre-drug administration and every 20 minutes after for two hours. Parameters measured were forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and forced expiratory flow at 25 percent to 75 percent of total volume (FEF25-75%). Subjects with asthma and COPD were also given nifedipine 20 mg three times daily, orally for two weeks, and tested biweekly during this period. All bronchodilators, beta-blockers, and long acting nitrates were withheld for five half-lives of the drug prior to test day. There was no adverse effect on the pulmonary function. We found a statistically significant improvement (p less than 0.05) in FEV1 after nifedipine. There was no tachyphylaxis at the end of two weeks. Nifedipine is safe in patients with asthma and/or chronic bronchitis.