Effect of nifedipine on salbutamol-induced bronchodilation in partially reversible airway obstruction.

The effects of the combination of oral nifedipine (20 mg) and inhaled salbutamol (400 mcg) were studied in ten stable patients with chronic partially reversible airway obstruction in a double-blind crossover design. Specific airway conductance (SGaw), forced expiratory volume in 1 second (FEV1), heart rate and blood pressure were recorded before and 30 min after administration of nifedipine or a placebo and 30, 60, 90, 150, 210 and 270 min after salbutamol inhalation. The mean value of FEV1 30 min after nifedipine was significantly (p less than 0.05) higher than after the placebo. The increase of SGaw and FEV1 produced by salbutamol was not significantly affected by pretreatment with nifedipine at any time. Nifedipine produced a significant increase of the heart rate which persisted throughout the study, but it did not influence blood pressure. No untoward effect was noticed during the study.