Asthma of physical effort and the effect of nifedipine and diltiazem

: In 13 patients with bronchial obstruction due to or enhanced by effort, the bronchodilatory effects of calcium antagonists (nifedipine and diltiazem) were studied and compared during the two-week treatment with each drug with a weekly interval. The appearance of bronchospasm at the 3d-5th minute after submaximal exercise (decrease of the volume of forced expiration during 1s by not less than 20% of the initial value) was regarded as a sign of asthma of effort. In 4 patients, bronchial obstruction in response to exercise was the only clinical sign of the disease, in 6 it was coupled with allergy, and in 3 patients, it aggravated the health status during exacerbation of bronchopulmonary infection. The patients were under observation during clinical remission of the disease. The clinical and instrumental data were estimated to reveal no well-defined correlation between the drugs. Both of them influenced bronchial patency, mainly at the level of the large and medium bronchi. Nifedipine was found to produce a more remarkable bronchodilatory effect.