Doxazosin in the treatment of mild or moderate essential hypertension: an echocardiographic study. Sixteen patients with mild or moderate essential hypertension received 1 to 8 mg/day of doxazosin (mean daily dose, 2.7 mg). Blood pressure reduction (supine and standing) was highly significant (p less than 0.001), and no significant changes in heart rate were observed. A significant reduction (p less than 0.01) in left ventricular mass was seen without a change in left ventricular systolic function. All side effects were mild, and only one patient withdrew from the study. 