Effect of ketotifen on the bronchodilation induced by salbutamol.

Twelve subjects with stable asthma each inhaled two puffs (200 micrograms) of salbutamol on 2 separate days 3 h after double-blind oral administration of ketotifen (two 1-mg capsules) or identical placebo. FEV1 was recorded before and at intervals for 4 h after inhalation of salbutamol. Overall, the FEV1 was significantly greater during the 4-hour period after premedication with ketotifen (p less than 0.02) and the difference between the effect of placebo and ketotifen was statistically significant at 120, 180 and 240 min after salbutamol (p less than 0.05).