VASODILATORS AND PLASMA-CATECHOLAMINE LEV ELS IN PATIENTS WITH MODERATE HYPERTENSIVE DISEASE

Vasodilators (verapamil, nifedipine, and prazosin) versus hypothiazide and clofelin were studied for their effects on resting and exercise b lood levels of catecholamines in 58 patients with moderate arterial hy pertension. Clofelin dicreased norepinephrine levels, whereas hypothia zide increased it at rest and during exercise test. The most marked ef fect on norepinephrine levels was produced by nifedipine, then prazosi n, particularly in patients with initially enhanced total peripheral v ascular resistance. Verapamil failed to substantially affect norepinep hrine levels. Due to the fact that the elevated levels of norepinephri ne may have a negative action, it is suggested that antiadrenergic age nts should be supplemented to a long-term therapy with nifedipine or p razosin.