Effect of doxazosin GITS on 24-hour blood pressure profile in patients with stage 1 to stage 2 primary hypertension

Objective To investigate the effect of the doxazosin gastrointestinal therapeutic system (GITS) on the 24 h blood pressure (BP) profile by ambulatory blood pressure measurements (ABPM) in patients with stage 1 to stage 2 primary hypertension. Methods and results Seventeen hypertensive patients -either untreated or after a two-week run-in/washout period-underwent office and ABPM monitoring before and six weeks after an open-label once-daily morning dose of 4 mg of doxazosin GITS, an alpha(1)-adrenoceptor antagonist. Fourteen patients responded; three did not. Data analyses refers to the responders: linear analysis demonstrated statistically significant reductions from baseline in daytime, night-time, and total 24 h means for systolic BP (SBP) (7-10 mmHg) and diastolic BP (DBP) (5-10 mmHg) after treatment, with no statistically significant change in heart rate (HR). Rhythm analysis demonstrated statistically significant reductions from baseline in mean mesor (8 mmHg), maximum (6 mmHg) and minimum (110 mmHg) values in SBP, and in mean mesor (5 mmHg), maximum (7 mmHg) and minimum (5 mmHg) values in DBP. Circadian rhythm parameters in BP and HR were not significantly altered by treatment. Treatment with doxazosin GITS was well tolerated. Conclusions A single morning dose of doxazosin GITS at 4 mg significantly reduced ambulatory SBP and DBP throughout a 24 h period while preserving a normal 24 h BP and HR rhythm profile in stage 1 to stage 2 hypertensives. (C) 2003 Lippincott Williams Wilkins.