comparison of the bronchodil atory effects of inhaled salbutamoland combiven t in asthmatic patients

a randomized, double-blind, crossover trial was designed to compare the acute effects of combivent and salbutamol on spirometric parameters in patients with moderate to severe asthma. nineteen patients with a mean baseline forced expiratory volume in 1 sec. (fev]) less than 65% predicted, were randomized on two separate days to receive two puffs of salbutamol (200 µg) or two puffs of combivent (200 µg salbutamol plus 40 µg of ipratropium bromide) by metered dose inhalers. on study days using spirometry, fev!, forced vital capacity (fvc), maximal mid-expiratory flow rate (mmef) and peak: expiratory flow rates (pefr) were measured at baseline and at 15, 60 and 180 minutes after drug administration. blood pressure and pulse rate were also determined before and 3 hours post drug inhalation. the results of this study show that combivent produces significantly greater improvement compared to salbutamol in all four spirometric parameters at 15, 60, and 180 minutes after drug treatment. the greatest differences between the bronchodilating effects of the two re!imens were observed at 180 minutes after drug inhalation. there were no clinically significant changes in heart rate or blood pressure. it may therefore be concluded that in patients with moderate to severe asthma, combivent provides better bronchodilation than salbutamo1 alone at clinically relevant doses without increasing side-effects