Prazosin versus hydrochlorothiazide as initial antihypertensive therapy in black versus white patients.

A randomized, drug-controlled trial was conducted to evaluate the comparative efficacy of hydrochlorothiazide versus prazosin in controlling mild diastolic hypertension in black and white patients. Serum lipid and lipoprotein levels were also studied. Overall, 22 men and 14 women, of whom 50 percent were black, aged 21 to 69 years, were randomly assigned to treatment with either of these two agents. If diastolic blood pressure was not reduced below 90 mm Hg, the other agent was added. Results showed that hydrochlorothiazide and prazosin lowered blood pressure effectively in both black and white patients, but there was a trend for more patients receiving hydrochlorothiazide to need combination therapy than for those receiving prazosin, regardless of ethnic status. Prazosin therapy reduced total cholesterol levels by 20.5 mg/dl and low-density lipoprotein cholesterol levels by 19.0 mg/dl, and hydrochlorothiazide increased total cholesterol levels by 11.4 mg/dl and increased low-density lipoprotein levels by 9.3 mg/dl; but no differences in triglyceride, high-density lipoprotein, plasma high-density lipoprotein2, or high-density lipoprotein3 levels were noted. Both agents were well tolerated in black and white patients. The combination of effective blood pressure control with no adverse effects on the serum lipid profile may make prazosin preferable to hydrochlorothiazide for treating mild diastolic hypertension in black as well as white patients.