Abstract
The effect of inhaled verapamil 20 mg on pulmonary functions and arterial blood gases in 15 patients with extrinsic bronchial asthma was studied in single-blind fashion. A significant decrease (p < 0.05) in airway resistance and a significant increase (p < 0.01) in specific conductance was observed after verapamil inhalation. A small increase (p < 0.1) was observed in forced vital capacity and peak expiratory flow rate after verapamil inhalation; however, this was not statistically significant. None of the parameters of pulmonary function tests showed a significant change after normal saline inhalation. A significant fall in Pa02 (p < 0.05) and Paco2 (p < 0.05) was noted after normal saline inhalation. Paco2 showed a significant fall (p < 0.01) after verapamil inhalation. Alveolar arterial oxygen gradient P(A-a)C>2 widened significantly (p < 0.001) after normal saline inhalation. A larger dose (20 mg) of verapamil inhalation produces a significant bronchodilator effect on large airways, but does not produce a significant change in arterial oxygen tension from the baseline value in patients with bronchial asthma.