beta-Adrenergic blockade with pindolol (LB-46) in mild to moderate asthma

Beta-adrenergic blockade may be hazardous in asthma and chronic obstructive lung disease. The beta-adrenergic antagonist pindolol (LB-46) has been suggested to be more tolerable in such patients. We gave intravenously both 0.4 mg pindolol and placebo to 24 mild to moderate asthmatic subjects in remission. In 23 subjects who completed the study, there was no significant difference in pulmonary function between the pindolol and placebo trials either after drug administration or following exhausting exercise after drug administration, although a trend toward reduced pulmonary function after pindolol was seen. Significant differences (P less than 0.05) were found after inhaled isoproterenol when FEV1 and peak expiratory flow rates were compared. We conclude that in this group of mild to moderate asthmatic subjects, there was no adverse effect from pindolol even during exercise-induced bronchospasm. The response to isoproterenol may have been slightly impaired, but the clinical meaning of this is unclear.