[Long-term use of prazosin alone and combined with propranolol in patients with essential hypertension]

Therapeutic efficiency and hemodynamic effects of prazosin were examined in 42 patients with essential hypertension in the course of prolonged treatment. Where the adrenoblocker showed low efficiency, the beta-blocker propranolol was added to the treatment scheme. The mechanism of the hypotensive effect was shown to be dependent on correlations between arteriolo- and venodilatation. In the presence of prevailing precapillary dilatation, BP dropped owing to reduced total and regional vascular resistance. If venodilatation was more pronounced, the hypotensive effect was due to reduced minute volume. The addition of propranolol eliminated the manifestations of sympathetic stimulation, enhanced the hypotensive effect and improved general condition of the patients. Combined treatment is indicated particularly in those cases of stable hypertension where prazosin alone has failed to produce an adequate effect.