Effect of inhaled alpha-blocker on airflow obstruction in asthma.

Abstract A controlled study of the effect on airflow obstruction of 30 mg of the alpha-blocker thymoxamine given by inhalation is reported in 10 patients with chronic stable asthma. No significant change in peak expiratory flow rate was seen with either thymoxamine or placebo in any patient. Alpha-adrenergic receptors are therefore unlikely to contribute significantly to resting bronchomotor tone in chronic stable asthma.