Comparison of trimazosin and methyldopa in hypertension.

Eighteen patients with hypertension participated in a double-blind, randomized study to evaluate the effect of trimazosin, methyldopa, and placebo on supine and standing blood pressure and heart rate. Of 6 patients on methyldopa, one developed drug fever (and was dropped from the study) and one developed impotence. None of 6 patients on trimazosin and none of 6 patients on placebo developed any adverse effects. The mean supine blood pressure on 900 mg trimazosin daily was 17.0/12.8 mm Hg lower than that on the first placebo trial (p less than 0.01) and 17.0/12.1 mm Hg lower than that on the second placebo trial (p less than 0.01). The mean supine blood pressure on 2,250 mg methyldopa daily was 17.8/12.4 mm Hg lower than that on the first placebo trial (p less than 0.01) and 16.8/13.0 mm Hg lower than that on the second placebo trial (p less than 0.01). The mean supine blood pressure was not significantly affected by placebo. Trimazosin, 900 mg daily, and methyldopa, 2,250 mg daily, were equally effective in lowering supine and standing systolic and diastolic blood pressure and did not affect supine or standing heart rate.