7-(2-HYDROXY-3-ISOPROPYLAMINOPROPOXY)INDENE HYDROCHLORIDE (1-(7-indenyloxy)3-isopropylaminopropane-2-ol hydrochloride,YB-2) has been reported to possess a potent beta-adrenergic receptor blocking activity with a mild intrinsic beta-sympathomimetic activity and a local anesthetic effect, and to be effective against ouabain-induced and epinephrine-induced arrhythmias.1-(7-indenyloxy)3-isopropylaminopropane-2-ol hydrochloride is a component of Indenolol hydrochloride, which is a mixture of 1-(7-indenyloxy)3-isopropylaminopropane-2-ol hydrochloride and 1-(4-indenyloxy)-3-isopr opylamino-2-propanol monohydrochloride. The antihypertensive effects of indenolol were evaluated in patients with WHO grades I and II essential hypertension (range 160/95 to 200/115 mm Hg) in a double-blind, placebo-controlled study after acute (12 patients) and 2-week treatment (seven patients). Indenolol (30 to 120 mg) reduced blood pressure in a dose-dependent fashion. Maximum reduction was 26 mm Hg for systolic and 17 mm Hg for diastolic pressure. Indenolol did not alter adrenergic reflexes (standing, cold application, and hand-grip) and did not induce any side effect. It possesses an antihypertensive activity associated with reduction of vascular resistance.