Initial clinical experience with ICI 141,292 (Visacor), a new selective beta 1-adrenoceptor blocker with ISA--a multicentre trial in 59 patients.

The objective of this placebo controlled double-blind multicentre (six centres) trial was to investigate the safety and efficacy of ICI 141,292 (Visacor), a new selective beta 1-adrenoceptor antagonist with modest intrinsic sympathomimetic activity (ISA), in hypertensive patients. Fifty-nine patients with mild essential hypertension were randomized to two of five treatment alternatives (placebo, 50 mg, 100 mg 200 mg or 300 mg of ICI 141,292) each given once daily for 2 weeks with a 4 week placebo period before (run in) and in between (wash out) active periods. Thus, each of the five treatments was evaluated in 20-24 patients. After 2 weeks (24 h after last dose) the reduction in recumbent blood pressure for all doses except 50 mg of ICI 141,292 was statistically significant and in the order of 6/4 mm Hg. Standing systolic blood pressure was reduced in a dose-dependent way but only significant for 200 mg of ICI 141,292 (8 mm Hg). Heart rate changes (delta) less than 4 beats/min) were not statistically significant for any dose. It is concluded that ICI 141,292 was well tolerated and had a significant but weak antihypertensive effect which might be explained by too much beta 1-adrenoceptor ISA.