Spirendolol (LI 32-468) is a β adrenergic receptor antagonist. It possesses high affinity for metabolic beta-adrenoreceptors which mediate glycogenolysis that is 100 times more potent than propranolol. In human volunteer studies, a single dose of 2 mg LI 32-468 elicited virtually no cardiac beta-adrenoreceptor blockade (predominantly beta-1), whereas a maximal metabolic beta-adrenoreceptor blocking effect (beta-2) was demonstrated. Spirendolol was a potent inhibitor of ocular beta-adrenoceptors, with a 9-12 fold selectivity over inhibition of beta-adrenoceptors in cardiac tissue. When applied topically, Spirendolol was more effective than timolol in decreasing intraocular pressure in normal albino rabbits.