Initial antihypertensive drug therapy: alpha blocker or diuretic. Interim report of a randomized, controlled trial.

A two-center, randomized, controlled trial designed to evaluate and compare an alpha blocker and a diuretic as initial antihypertensive drug treatment is currently in progress. Approximately 100 men and women, aged 30 to 69 years, are being randomly assigned to treatment with either of these two agents. If diastolic blood pressure is not reduced to its target level and is 85 mm Hg or higher, the alternate agent is added. The alternate agent is substituted if a patient does not tolerate the assigned agent. This preliminary report presents data concerning 62 patients who completed at least three of the planned 12 months of drug treatment. At that point, the alpha blocker prazosin and the diuretic hydrochlorothiazide were similar in their ability to lower the average diastolic blood pressure to normal levels. Serum total cholesterol and triglyceride levels declined in prazosin-treated patients but increased in hydrochlorothiazide-treated patients, a difference that was statistically significant. No significant weight change, a possible confounding variable, occurred in either group. More patients were unable to tolerate prazosin than were unable to tolerate hydrochlorothiazide (10 of 30 receiving prazosin, compared with three of 32 receiving hydrochlorothiazide). For those able to continue with prazosin, the favorable lipid response appears to be an asset in regard to reducing possible atherogenic effects of treatment.