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

Abstract

Rilmenidine (RIL) is a novel antihypertensive drug selectively acting at the sites of imidazoline receptors. Compared with diuretics, /i-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 /i-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 a2-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 signifi-cantly 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. The long-term treatment was proof of excellent clinical and biochemical acceptability of RIL even in the elderly. In addition, RIL was shown to be effective in high risk populations, such as diabetics, in whom there was no alteration of glycolipid metabolism. Due to its pharmacokinetic properties, RIL is not contraindicated in hepatic or renal failure (except for patients with a creatinine clearance ` 15 mL/min).Therefore, RIL may be considered as a first-line treatment for hypertension. If the regression of left ventricular hypertrophy and the blood pressure lowering effect throughout the entire 24 h during once-a-day monotherapy were demonstrated, RIL has a more favorable profile than well-known monotherapies for cardiovascular risk factor due to its effects on glycolipid metabolism. Am J Hyper- tens 1992;5:99S - 105S. © 1992 by the American Journal of Hypertension, Ltd.