Effects of Different Dosages of the Calcium Antagonist Verapamil in Exercise- and Methacholine-Induced Bronchospasm in Children with Chronic Asthma

The protective effect of 5 mg/2 ml and 10 mg/4 ml of the calcium antagonist verapamil on methacholine challenge and exercise were evaluated in two groups of asthmatic children. Saline solution was used as placebo. No significant differences were seen in baseline pulmonary function in and within groups. There was a minimal but significant bronchodilation 30 minutes after inhalation of verapamil 5 mg/2 ml. The drug did not reduce methacholine sensitivity at any dosage. After exercise, verapamil 5 mg/2 ml showed a significant change in the maximum percentage drop in forced expiratory volume in 1 second (FEV₁ compared with placebo. This was not the case for the group treated with a double dosage. At this time, there is no evidence for a major role of verapamil in the treatment of childhood asthma.