THE EFFECTS OF RILMENIDINE AND ATENOLOL ON MENTAL STRESS, DYNAMIC EXERCISE AND AUTONOMIC FUNCTION IN MILD-TO-MODERATE HYPERTENSION

1 The effects of 4 week treatment with rilmenidine or atenolol on test s of mental stress, dynamic exercise, autonomic function and psychomet ric tests were evaluated in a randomized, double-blind, placebo-contro lled, cross-over study. 2 After a 4 week placebo run-in, 12 patients w ith essential hypertension (blood pressure [BP] 160/95 +/- 15/7 mmHg) received rilmenidine 1-2 mg day(-1), and atenolol 50-100 mg day(-1), e ach for 4 weeks, with a 4 week placebo wash-out between drug treatment s. 3 Both agents produced a comparable reduction in supine and erect B P. During the mental arithmetic test, BP and heart rate (HR) responses were similar for rilmenidine and atenolol. 4 During bicycle exercise, the increase in HR was significantly greater after rilmenidine (+ 50 vs 41 beats min(-1), P = 0.04). During recovery, the areas under the c urve for diastolic BP (46 450 vs 51 400 mmHg s, P = 0.02) and HR (49 4 45 vs 63 597 beats min(-1) s, P = 0.001) were significantly less with atenolol than rilmenidine. 5 Neither rilmenidine nor atenolol affected mental performance as judged by arithmetic and psychomotor tests. Phy siological responses to autonomic function tests (deep breathing, faci al immersion, isometric handgrip and cold presser) were preserved with both drugs. The standing to lying ratio was higher on atenolol (P = 0 .01.) and Valsalva ratio was higher on rilmenidine (P = 0.03). 6 In co nclusion, rilmenidine and atenolol exerted comparable antihypertensive effects both at rest and during mental and dynamic stress. Atenolol a ttenuated HR responses to dynamic exercise and the Valsalva manoeuvre; rilmenidine did not interfere with the physiological responses of BP and HR during autonomic function tests.