The effect of inhaled verapamil on allergen-induced bronchoconstriction.

In eight patients with extrinsic bronchial asthma the effect of inhaled verapamil (3 and 6 mg) was compared with saline on bronchial challenge with extracts of Dermatophagoides pteronyssinus. There was no significant difference in the baseline FEV1 before and after inhalation of saline or verapamil 2.5 mg/ml. However, verapamil at a higher concentration (5 mg/ml) caused bronchoconstriction in four patients who had to be excluded from the part of the study. Verapamil at both these concentrations failed to have an effect on the allergen-induced bronchoconstriction. These findings suggest that verapamil given by inhalation does not prevent mediator release from the lung mast cells following specific allergen challenge.