The value of atropine in the documentation of reversible airways obstruction.

Thirteen randomly selected outpatient asthmatics were treated with nebulized atropine sulfate, isoproterenol and the combination of these drugs in a randomized double-blind trial. Sequential pulmonary function parameters, cardiovascular changes and side effects were monitored over a 60-minute period following drug administration. Both atropine and isoproterenol produced significant and equivalent improvement in mean forced expiratory flow rates; the combination of drugs produced significantly greater improvement at each time interval without producing significant cardiovascular changes or side effects. Four patients failed to show clinically significant increases in expiratory flow rates following isoproterenol alone; two of these four improved following atropine alone, while two improved only when given the combination of drugs. The addition of an anti-cholinergic agent may provide a more precise assessment of reversibility of obstructive airways disease in the individual patient.