Pharmacology of GYKI-41 099 (chlorpropanol, Tobanum) a new potent beta-adrenergic antagonist.

The compound GYKI-41 099, as a beta-adrenergic antagonist, is 3-8 times more potent than propranolol in vitro and in vivo. Its antiarrhythmic effectiveness surpasses that of propranolol and pindolol inhibiting the ouabain arrhythmia in dogs and cats. GYKI-41 900 has a negligible cardiodepressant activity; it is not cardioselective. The compound shows a rapid and long lasting effect. There was a prolonged elimination of the radioactivity after the injection of 14C-41 099 to rats and dogs. The half life of the unlabeled substance in humans was more than 10 hours.