A multicenter study of doxazosin in the treatment of severe essential hypertension

The antihypertensive efficacy and safety of doxazosin, a selective α₁-inhibitor, were assessed in 33 severely hypertensive patients. The study involved three phases: a 1-day baseline period, a 32-day period in which patients received doxazosin, 1 to 16 mg, once daily, and a 4-week maintenance period. All patients were considered therapy successes (sitting diastolic blood pressure either ≤90 mm Hg or ≥10 mm Hg reduction) at a mean daily dose of 8.1 mg. Twenty-seven patients (82%) achieved good blood pressure control (sitting diastolic blood pressure ≤90 mm Hg) at a mean dose of 6.7 mg once daily. By the final treatment visit, mean systolic/diastolic blood pressures in the sitting and supine positions were significantly reduced by $\text{40}\text{29}$ and $\text{37}\text{28}\text{mm Hg}$ from a mean baseline of $\text{180}\text{121}$ and $\text{181}\text{121}\text{mm Hg}$ to final visit values of $\text{140}\text{91}$ and $\text{144}\text{92}\text{mm Hg}$, respectively (p < 0.05). Eleven patients experienced one or more side effects that were mild or moderate and disappeared or were tolerated with continued therapy. During the study no abnormal laboratory test findings were identified by the investigators. The investigators' global assessment of the efficacy and toleration of once-daily doxazosin therapy was excellent or good for 31 (94%) patients and fair for the remaining two patients.