Double-blind comparison of doxazosin and enalapril in patients with mild or moderate essential hypertension. The antihypertensive efficacy and safety of doxazosin and enalapril were compared in the general practice setting (n = 54). Both agents produced comparable, statistically significant (p less than 0.05) reductions in mean blood pressure with no clinically relevant changes in heart rate. Side effects in the two groups were mild or moderate and disappeared or were tolerated with continued treatment. Doxazosin, in contrast to enalapril, produced a significant (p less than 0.05) reduction in the total serum cholesterol concentration, a reduction in the level of triglycerides, and a favorable increase in the high-density lipoprotein/total cholesterol ratio. The reduction in calculated coronary heart disease risk produced by doxazosin (-27.58%) was highly significant (p less than 0.0002) and greater than that produced by enalapril (-18.49% p less than 0.02). 