Indenolol: a new antihypertensive agent: efficacy, toxicity, and hemodynamic effects in a crossover double-blind study with metoprolol.

The antihypertensive efficacy of a new agent, indenolol, was compared with that of the well-established antihypertensive drug, metoprolol, and its hemodynamic effects were investigated using echocardiography. Eighteen hypertensives completed a double-blind, crossover, randomized study using indenolol and metoprolol. Two four-week courses with indenolol or metoprolol were preceded and followed by a two-week placebo period; the total duration of the study was 14 weeks. Indenolol proved to be significantly more effective than metoprolol in decreasing blood pressure values at rest (P less than .05). Furthermore, three patients that failed with metoprolol were successfully treated with indenolol. Both drugs induced a significant decrease in cardiac output that was mediated mainly through a reduction in heart rate, because stroke volume, left ventricle circumferential fiber shortening velocity, and ejection fraction were not significantly reduced by either drug. However, after indenolol, a significant direct relationship was found between the basal values of both cardiac output (r = .809) and total peripheral resistance (r = .800), and the reduction of these parameters. On the contrary, after metoprolol only, the correlation between the basal value of cardiac output and its reduction was significant (r = .790).