Principal results of the Hypertension and Lipid Trial (HALT): a multicenter study of doxazosin in patients with hypertension.

The Hypertension and Lipid Trial (HALT) was undertaken to assess the efficacy and safety of doxazosin, a selective alpha 1- adrenergic blocker, in patients with hypertension in a clinical practice setting. The effects of doxazosin on office blood pressure, changes in lipid profiles, and theoretic coronary disease risk were studied. In an open, noncomparative, multicenter trial, 851 patients were studied for a maximum of 16 weeks. Doxazosin significantly reduced mean sitting systolic blood pressure (SBP) and diastolic blood pressure (DBP) by 15.2/12.5 mm Hg and standing SBP and DBP by 16.1/12.7 mm Hg in the total study population (n = 807; p = 0.0001), with no significant effect on heart rate. Mean total cholesterol levels were significantly reduced by 2.7%, low-density lipoprotein cholesterol levels by 2.4%, and mean triglyceride levels by 3.4% (all p values < 0.05). High-density lipoprotein (HDL) cholesterol levels were essentially unchanged. The mean ratio of total to HDL cholesterol was significantly reduced (p < 0.05). Mean predicted 5-year coronary disease risk was significantly reduced with doxazosin therapy by 14.7% in previously untreated patients (p < 0.0001) and by 1.7% in patients who were previously receiving antihypertensive therapy (p < 0.05). The drug was well tolerated. This study demonstrates that antihypertensive therapy with doxazosin can favorably affect coronary disease risk factors and reduce predicted coronary disease risk.