The effects of tamsulosin on vital signs in two multicenter, placebo-controlled studies

Although effective in the treatment of benign prostatic hyperplasia, α blockers as a class were initially developed to treat hypertension. Tamsulosin is a long acting, partially selective blocker of the α_1A adrenoceptor subtype, which mediates prostatic smooth muscle tone. In two previously reported placebo-controlled trials of tamsulosin's efficacy and safety in the treatment of benign prostatic hyperplasia, orthostatic changes in blood pressure and pulse rate were tested to determine tamsulosin's effects on vital signs. Subgroup analyses of sitting vital signs in controlled hypertensive, uncontrolled hypertensive, and normotensive patients were included. Tamsulosin had minimal effects on blood pressure regardless of baseline hypertensive status. The overall incidence of symptoms indicative of orthostasis (symptomatic postural hypotension, syncope, or vertigo) was 1.4%. Only 0.2% of patients treated with tamsulosin 0.4 mg/day and 0.4% of those treated with tamsulosin 0.8 mg/day experienced symptomatic postural hypotension. There were no clinically significant first dose effects, indicating that tamsulosin does not require dose titration and is safe and well tolerated in patients with without hypertension.