Evaluation of the Effects of Prazosin on Resistant Diastolic Hypertension With a Focus on Sex Difference

Background: Despite all the focus on systolic blood pressure (SBP), few studies exist on high diastolic blood pressure (DBP) treatment between the different genders. In this study, we investigated the effects of prazosin as an additional treatment for refractory DBP. Methods: Totally, 75 nonblack adults were enrolled in this study with primary hypertension and DBP >100 mm Hg as isolated diastolic hypertension or systolic-diastolic hypertension. All the patients were treated with 1 or more drugs from the 5 major antihypertensive group drugs (ACE-I, ARB, diuretic, Ca-channel blockers, and beta-blockers). If hypertension did not respond to these drugs, prazosin was added at a mean dose of 1–2 mg (1.6 mg) daily. Result: Many of the patients needed additional low doses of prazosin for the control of DBP. The response of the females was significantly better than that of the males to the 5 major antihypertensive drugs (P=0.001) . This study showed that the 5 major drug groups, albeit conferring good SBP control (25.8% reduction in SBP), in the majority of the patients only caused a 10% decrease in DBP. However, prazosin led to a 21.8% decrease in DBP and a 9.5% decrease in SBP. Consequently, prazosin could be an effective drug in controlling resistant DBP with minimal side effects. Conclusions: Low-dose prazosin as an additional drug to other major antihypertensive drugs with minor and transient complications can be reliably effective in reducing resistant DBP.