PHARMACOLOGICAL AND TOXICOLOGICAL PROPERTIES OF TWO NEW β-ADRENERGIC RECEPTOR ANTAGONISTS

Studies involving the responses of respiratory and uterine smooth muscle and cardiac muscle to isoproterenol have revealed potent and selective β-adrenergic blocking action as a property of two phenethanolamine compounds bearing a methylsulfonamido radical at the para position on the benzene ring. These compounds had no other significant peripheral actions, including no local anesthetic action, and only limited effects on the central nervous system. Acute toxicity studies in mice, rats, dogs, and rabbits, and subacute toxicity studies in rats and dogs, indicated extremely low toxic liability. Neither compound had harmful effects on the fetuses of mice or rabbits dosed during critical days of pregnancy.