An open, noncomparative study of doxazosin in essential hypertension: experience in general practice in The Netherlands. The antihypertensive efficacy, safety, and lipid effects of doxazosin, a selective alpha 1-inhibitor, were assessed in a general practice setting. Three hundred twenty-six patients were entered into the study, which involved three phases: (1) a 2-week baseline period, (2) an 8-week period in which patients received 1 to 8 mg of doxazosin once daily, and (3) a 4-week maintenance period. After 12 weeks, 78.8% of efficacy-evaluable patients were considered therapy successes (sitting diastolic blood pressure either less than or equal to 90 mm Hg with greater than or equal to 5 mm Hg reduction from baseline or greater than or equal to 10 mm Hg reduction from baseline). The mean daily dose in patients considered a therapy success was 2.8 mg. By the final visit, sitting systolic/diastolic blood pressures of these patients were reduced by 16.4/13.5 mm Hg from a mean baseline of 170/106 mm Hg. The investigators' global assessment of efficacy of once-daily doxazosin therapy was excellent or good for 70% of patients. Of the 326 patients, 30.7% reported a total of 160 side effects; 78% of the side effects were mild or moderate in severity, and 24 patients (7.4%) discontinued treatment because of adverse experiences. The investigators' global assessment of toleration was excellent or good for 87% of patients. Doxazosin produced a significant decrease in total cholesterol (p = 0.02) and triglyceride (p less than 0.001) levels. From baseline to final visit there was also a highly significant reduction of 17% (p less than 0.001) in calculated risk score for coronary heart disease on the basis of the Framingham Heart Study risk equation. 