Effect of prazosin on serum lipids.

On the premise that serum lipids may be correlated with the increased mortality from coronary heart disease seen in Japan despite successful antihypertensive therapy, we undertook an open, noncomparative study to determine the effect of prazosin on serum lipid. All patients were adults (mean age of 59, with a range of 45 to 72), and all had a sitting blood pressure greater than 160 mm Hg systolic or 90 mm Hg diastolic. After a stabilization period of 2 to 4 weeks, prazosin was started at 0.5 mg t.i.d. This dose was maintained for 1 week and was then titrated upwards to achieve optimal antihypertensive effect. Maximum dose permitted was 12 mg/day. All patients were treated for at least 12 weeks. Concomitant therapy was allowed in patients who had been stabilized on other drugs prior to entry into the study. At the end of 12 weeks of therapy, prazosin (at an average dose of 4.5 mg) had lowered blood pressure by an average of 10/9 mm Hg in the sitting position, 11/7 mm Hg in the supine position, and 19/13 mm Hg in the standing position. Pulse rate did not change. Total cholesterol and triglycerides were essentially unchanged, and LDL and VLDL decreased by 4.5%. However, high density lipoprotein (HDL) cholesterol increased by 12.5%. These changes were statistically significant and yielded an increase of 20.3% in the cholesterol ratio. No side effects were noted in any patient, and none of the patients discontinued therapy during the study. This is an ongoing study, in which 14 patients have so far completed the 12 weeks of therapy. On the basis of these preliminary results, prazosin would seem to be an effective and safe antihypertensive agent with considerable favorable effects on serum lipids.