Open assessment of the effect of prazosin on plasma lipids.

Seventeen patients with newly diagnosed hypertension, or with hypertension not optimally controlled by previous treatment, completed an open, noncomparative study on the effects of prazosin on plasma lipids. Patients with diabetes mellitus, raised triglycerides, or alcohol consumption of over 250 g/week, and patients on concomitant treatment with drugs known to affect lipid levels were excluded. Diastolic blood pressure varied between 90 and 115 mm Hg. Prazosin was given initially in a dose of 1 mg three times a day for the first 2 weeks. If the drug was well tolerated but the blood pressure response was not satisfactory, the dose was increased at fortnightly intervals to 2 mg t.i.d., 4 mg t.i.d., and to a maximum of 6 mg t.i.d. Patients were reviewed twice before the start of prazosin treatment, the intervals between visits being not less than 2 weeks, and after 2, 4, 6, 8, and 12 weeks of prazosin treatment. Patients attended in the morning after an overnight fast of 12-16 h. Duplicate measurements of blood pressure and heart rate were recorded after 5 min lying down and after 2 min standing. Blood was taken for measurements of triglycerides, total cholesterol, and high density lipoprotein (HDL) cholesterol, as well as other hematological and biochemical parameters. Prazosin reduced systolic and diastolic blood pressures significantly. There was a slight tendency to increase HDL and reduce total cholesterol, but in neither case were these changes statistically significant. Triglyceride levels did not change significantly either.