Antihypertensive effect of trimepranol, a new beta-blocking agent.

Trimepranol (TMP) is a new propranolol-like, non-selective beta-adrenoreceptor blocking drug. Its antihypertensive effect versus placebo was evaluated in a double-blind corss-over study in 25 ambulatory patients, whose supine diastolic blood pressure (BP) was at least 95 mm Hg. After four weeks treatment with placebo, the dose of TMP was titrated weekly until the supine diastolic BP was below 95 mm Hg or intolerable side effects occurred. The trimepranol dose thus determined was 10 mg bid for three patients, 20 mg bid for twelve patients and 40 mg bid for ten patients. The subsequent double-blind cross-over study consisted of two six weeks treatment periods, either with trimepranol followed by placebo (Group I) or in reverse order (Group II). BP and heart rate at the end of these periods were compared. Supine BP fell from 156 +/- 3/105 +/- 2 mm Hg at the end of placebo periods to 140 +/- 2/93 +/- 1 mm Hg (p less than 0.001) for systolic and diastolic BP at the end of trimepranol periods, when the data of Groups I and II are pooled. In 19 out of 25 patients, supine diastolic BP declined below 95 mmHg during the trimepranol period. A statistically significant correlation was found between the antihypertensive and bradycardic effects of trimepranol. Mild side effects occurred in the heart volumes of the patients. We conclude that bid trimepranol is an effective antihypertensive agent.