Doxazosin in hypertension: results of a general practice study in 4809 patients

The safety and efficacy of the selective alpha 1-adrenoceptor antagonist doxazosin were evaluated in a 10-week open, non-comparative multicentre trial in 4809 hypertensive patients (sitting diastolic blood pressure 95-114 mmHg) in general practice. Multiple coronary risk factor were present in the study population (mean age 58.4 years, 1486 patients > or = 65 years) on entry: mean blood pressure was 173/103 mmHg, 21% were cigarette smokers, and baseline blood cholesterol (mean 6.84 mmol/l) exceeded 6.5 mmol/l in 56% and 5.2 mmol/l in 88% of patients. In all, 4385 patients (91%) completed the study, including 89% of those > or = 65 years. Blood pressure was controlled (diastolic BP < or = 90 mmHg or a reduction > or = 10 mmHg) in 81% of patients with a mean reduction of 21/15 mmHg and a mean final daily dose of 2.9 mg doxazosin. Adverse events were reported in 827 patients (17%), were severe in 72 (1.5%), and led to withdrawal in 269 patients (5.7%). Dizziness and related symptoms (6%; severe 1.1%), headache (3.8%) and fatigue (2.6%) were most frequent; dizziness led to study withdrawal in 1.3% of patients. Fainting or syncope occurred in 13 patients (0.3%). Differences in adverse event frequency between younger (< 65) and older patients were small (dizziness: younger 5.1%, older 8.1%). Troublesome postural hypotension was uncommon as a clinical problem. Modest but statistically significant reductions occurred in blood total (4.09%) and LDL (5.13%) cholesterol. These results are in accord with those of controlled studies, and help confirm the suitability of doxazosin as part of a multiple risk factor approach to the management of hypertension.