Review of orthostatic tests on the safety of tamsulosin, a selective alpha1A-adrenergic receptor antagonist, shows lack of orthostatic hypotensive effects.
Two phase III studies with tamsulosin, a selective alpha1A-adrenergic receptor antagonist, were conducted to evaluate the safety and efficacy of the standard treatment doses of 0.4 mg/day and 0.8 mg/day in patients with symptoms of benign prostatic hyperplasia (BPH). These large-scale clinical trials were the first to include extensive testing for possible drug-induced orthostatic hypotension (OH). The frequency of positive orthostatic tests and magnitude of vital sign changes were compared among tamsulosin and placebo-treated groups. The results indicate that tamsulosin up to 0.8 mg/day does not induce higher risk of OH than that of placebo. Data from post-marketing surveillance (PMS) studies of tamsulosin indicate that the incidence of hypotension and syncope is extremely low in community-dwelling elderly men treated for BPH. From the results of the phase III studies, PMS studies and an active-controlled clinical pharmacology study, we conclude that the orthostatic test is a useful and convenient method to evaluate the risk of OH and syncope during the investigational stage.
Yasukawa
K
K
Yamanouchi Pharmaceutical Co. Ltd, Tokyo, Japan.
Swarz
H
H
Ito
Y
Y
D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists / Q000009:adverse effects*; D017326:Clinical Trials, Phase III as Topic; D006801:Humans; D007024:Hypotension, Orthostatic / Q000139:chemically induced*; D008297:Male; D015337:Multicenter Studies as Topic; D011470:Prostatic Hyperplasia / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D018340:Receptors, Adrenergic, alpha-1; D013449:Sulfonamides / Q000009:adverse effects*; D000077409:Tamsulosin
C547713:ADRA1A protein, human; D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists; D018340:Receptors, Adrenergic, alpha-1; D013449:Sulfonamides; D000077409:Tamsulosin