Rilmenidine: a novel approach to first-line treatment of hypertension

Rilmenidine (RIL) is a novel antihypertensive drug selectively acting at the sites of imidazoline receptors. Compared with diuretics, beta-blockers, Ca2+ antagonists and angiotensin converting enzyme inhibitors, the four major groups recommended by the US Joint National Committee as first-line antihypertensive drugs, RIL appears to meet the same criteria of efficacy, safety, and acceptability. Rilmenidine dose-dependently decreases blood pressure (BP), acting as a vasodilator by decreasing vascular resistance through inhibition of the adrenergic nervous system, even while the BP changes due to standing and exercise. In comparison with placebo, RIL significantly decreased BP. In double-blind comparative trials versus first-line diuretics and beta-blockers, RIL normalized BP in approximately 60% patients, showing a similar efficacy to other drugs. In contrast with hydrochlorothiazide, RIL decreased total cholesterol and did not change plasma potassium levels. No tachyphylaxis was observed during long-term treatment. Central side effects, which have contributed to the limitation of the use of alpha 2-agonists as second- or third-line therapy for hypertension, were significantly less frequent with RIL than with clonidine or methyldopa. Indeed, the incidence of dry mouth and drowsiness during double-blind comparative trials versus clonidine and methyldopa was significantly lower with RIL. This absence of central side-effects was confirmed in double-blind comparative trials versus hydrochlorothiazide and atenolol. In contrast with clonidine, no sodium retention or weight gain were observed during chronic treatment with RIL.(ABSTRACT TRUNCATED AT 250 WORDS)