Comparison of acute bronchodilator effects of inhaled ipratropium bromide and salbutamol in bronchial asthma

Both salbutamol (sal) and ipratropium (ipra) are effective bronchodilators in asthma patients. However, the issue of their relative status remains unresolved and the clinical factors affecting the responses have also not been adequately defined. The two drugs were compared in 44 asthmatics in a double-blind, randomized crossover, placebo-controlled study. There were four test days on which each patient received the following sequences of drugs: sal-sal-ipra, sal-sal-placebo, ipra-ipra-sal, and ipra-ipra-placebo. Baseline forced expiratory volume in 1 sec(FEV1) was similar on the four days. The change in FEV1 produced by salbutamol when given as the first bronchodilator was 0.50+/-0.30 L as compared to a change of 0.39+/-0.27 L produced by ipratropium (p<0.01). Both salbutamol and ipratropium resulted in statistically similar further improvements in FEV1 when given as the second drug. There was, however, a wide patient-to-patient variability in response, with some patients showing greater improvement with salbutamol and others with ipratropium. Younger patients showed a greater response to salbutamol as compared to older patients, while no such difference was observed with ipratropium. Males responded better to both the drugs as compared to females. It was concluded that both salbutamol and ipratropium are effective bronchodilators in asthma patients, although the overall response to salbutamol appears to be superior. However, some patients may respond better to one or other of the two drugs. Sequential administration of the two drugs may be a justified therapeutic approach as some patients show have further improvement with use of the second drug.