Timolol: a preliminary report of its pharmacological properties and therapeutic efficacy in angina and hypertension.

Timolol (MK 950) is a new beta-adrenergic receptor blocking drug. It has little or no membrane stabilising ('quinidine-like') or partial agonist (intrinsic sympathomimetic) activity and thus resembles sotalol. On a weight for.weight basis, timolol is more potent than sotalol or propranolol. A 2.5 mg dose of timolol causes about the same reduction in resting heart rate as 20mg of propranolol. Results of placebo-controlled and of comparative trials with other beta-adrenergic receptor blocking drugs, have shown that timolol effectively lowers blood pressure without producing orthostatic or exercise hypotension. Findings of an international multicentre trial in angina pectoris, indicate that timolol is effective in reducing the frequency of anginal attacks and the consumption of glyceryl trinitrate for their relief.