DOUBLE-BLIND, RANDOMIZED STUDY OF THE EFFICACY, TOLERANCE, AND REBOUND EFFECTS OF THE ANTIHYPERTENSIVE DRUG RILMENIDINE - COMPARATIVE-EVALUATION WITH CLONIDINE

Antihypertensive compounds such as clonidine have been widely used to treat arterial hypertension. Nevertheless, their use has been limited because of central nervous system side effects (eg, sedation and depre ssion) and other side effects (eg, mouth dryness) and because of the r ebound hypertensive effect seen after interruption of treatment. This double-blind study was conducted to compare clonidine with rilmenidine , a new antihypertensive agent that acts on the central and peripheral imidazoline receptors. Fifty-nine patients were randomly assigned to receive either rilmenidine 1 to 2 mg/day orally (n = 30) or clonidine 0.15 to 0.30 mg/day orally (n = 29) for 8 weeks. Placebo was administe red for 7 days after the end of active treatment to compare the effect s produced by discontinuation of each drug. Rilmenidine significantly decreased arterial pressure from 161/101 mmHg to 144/91 mmHg (P < 0.00 1) and did not alter heart rate (74 beats/min before and after treatme nt). Clonidine also significantly decreased arterial pressure from 159 /99 mmHg to 139/87 mmHg (P < 0.001) but also decreased heart rate (fro m 76 beats/min to 73 beats/min). After rilmenidine treatment was disco ntinued, arterial pressure returned to initial values (161/99) and hea rt rate remained stable (74 beats/min). After discontinuation of cloni dine, arterial pressure remained slightly above the initial values (16 3/100 mmHg) and heart rate increased significantly to 79 beats/min. Si de effects were seen in a lower percentage of patients treated with ri lmenidine compared with those treated with clonidine. We conclude that rilmenidine's antihypertensive efficacy is statistically similar to t hat of clonidine. Patients tolerated rilmenidine much better than clon idine, and there was no evidence of a rebound effect when rilmenidine therapy was withdrawn.