The safety and efficacy of once-daily
terazosin as monotherapy were evaluated in five randomized, double-blind, placebo-controlled studies in which 351 patients with mild to moderate
hypertension participated. The five studies included two dose-titration studies and three fixed-dose studies. In the dose-titration studies,
terazosin doses were titrated at weekly intervals until supine diastolic blood pressure was below 90 mm Hg. In the fixed-dose studies, titration continued until a predetermined dosage level of
terazosin or corresponding placebo was reached. The dose of
terazosin ranged from 1 to 40 mg once daily, and responses were assessed after a four-week course of
therapy at a constant dosage level.
Terazosin administration resulted in significantly greater mean decreases in supine diastolic blood pressure in comparison with placebo in four of the five studies. Similar decreases were observed for supine systolic and standing blood pressures in selected studies. In all five studies,
terazosin caused a significant decrease in supine and standing blood pressures from baseline to the final visit. Adverse experiences occurring with a significantly greater prevalence rate in
terazosin-treated versus placebo-treated patients and 7 percent of placebo-treated patients),
asthenia (17 percent of the
terazosin group and 4 percent of the placebo group), and peripheral
edema (10 percent of the
terazosin group and 3 percent of the placebo group). On the basis of these studies, it appears that
terazosin, when administered once daily as monotherapy, is both safe and effective for the treatment of mild to moderate
hypertension.