Clinical experience with doxazosin in general medical practice in The Netherlands. This study was designed to investigate the efficacy and toleration of once-daily doxazosin in the treatment of essential hypertension (sitting diastolic blood pressure 95 to 115 mm Hg) in a general medical practice. Fifty-three patients with mild or moderate essential hypertension entered a study of 14 weeks' duration. This consisted of a baseline run-in period of 2 weeks, a dose-adjustment phase with doxazosin (8 weeks), and a maintenance phase of 4 weeks. Doxazosin was initiated at 1 mg/day, and every 2 weeks the dose was doubled unless blood pressure was normalized (sitting diastolic blood pressure less than or equal to 90 mm Hg with greater than or equal to 5 mm Hg reduction from baseline) or significant side effects emerged. The maximum daily dose administered was 8 mg. Doxazosin produced a significant (p less than 0.05) final mean change in sitting blood pressure of -17.4/-12.2 mm Hg at a final mean daily dose of 4.1 mg. Heart rate was not significantly altered. A nonsignificant decrease in total cholesterol concentration (-2.66%, p = 0.06) and triglycerides (-8.80%, p = 0.09) was also observed. The effect of doxazosin on blood pressure and serum cholesterol resulted in a significant (p less than 0.001) reduction of 19% in calculated risk of coronary heart disease. The investigators' assessment of patient toleration of doxazosin was excellent or good in 86.8% of patients. 