The effect of aerosolized verapamil on the response to isoproterenol in asthmatics.

Calcium antagonists, like verapamil, may play a beneficial role in the management of airway disease. However, the effect that verapamil plays in modulating the response to beta-adrenergic bronchodilator therapy has not been well characterized. We found that inhaled verapamil, 3 mg, had little effect on the bronchodilator response to sequential inhalations of isoproterenol. Also, verapamil had no significant effect on isoproterenol's protection against methacholine-induced bronchospasm in a group of 8 mild asthmatics. These studies support the safe use of these agents in combination but do not demonstrate any additive or synergistic benefit.