Assessment of the relative safety of the beta-blockers ICI 141,292 and atenolol in patients with bronchial asthma

ICI 141,292 is a β-blocker with β1-selective partial agonist activity. To study its cardioselectivity in humans, comparable β-blocking doses of 200 mg ICI 141,292 and 100 mg atenolol were given to 12 patients with stable bronchial asthma. Both drugs significantly reduced the midexpiratory flow rate at 50% of vital capacity, whereas no significant reduction in FEV1 or peak expiratory flow rate were observed. It is concluded that the cardioselectivity of ICI 141,292 did not differ significantly from that of atenolol. Since they both had a measurable effect on respiratory mechanics, they should probably not be prescribed in bronchial asthma, or only with the greatest possible caution.