beta‐Adrenoceptor blocking activity and duration of action of pindolol and propranolol in healthy volunteers.

Abstract

The beta‐adrenoceptor blocking activities of pindolol and propranolol have been investigated in healthy male volunteers. Pindolol was about forty times more potent than propranolol in reducing isoprenaline‐ induced tachycardia. Pindolol (5 mg) and propranolol (u99 mg) were approximately equiactive in reducing exercise‐induced tachycardia, 2 h after oral administration. The duration of action of pindolol is significantly longer than that of propranolol; 24 h after pindolol (kmg), 36+/‐5% of the masimum effect were still present, and after propranolol (100 mg) 16+/‐4% remained. Despite the long duration of action of pindolol, there was no evidence for cumulation during oral administration of 5 mg t.d.s. for 5 days. 1976 The British Pharmacological Society