Nifedipine enhances the bronchodilator effect of salbutamol.

Ten male asthmatic volunteers each inhaled two puffs (200 micrograms) of salbutamol on two separate days 30 minutes after double blind oral administration of either 20 mg nifedipine or identical placebo. FEV1 was recorded before and at intervals for four hours after inhalation of salbutamol. Overall the FEV1 was significantly greater during the four hour period after premedication with nifedipine (p less than 0.025) and the difference between the effects of placebo and nifedipine was greatest four hours after salbutamol (p less than 0.005). These results suggest that nifedipine prolongs the bronchodilator action of salbutamol in vivo.