tcsc2429 Terazosin

Terazosin is a selective alpha1-antagonist used for treatment of symptoms of benign prostatic hyperplasia (BPH).

Target: Alpha-1 Adrenergic Receptor

Terazosin is selective for alpha 1A-adrenoceptors which appear to dominate in the human prostate; the therapeutic relevance of this selectivity remains to be assessed in clinical studies [1]. Administration of terazosin 1 mg orally for 28 d. Terazosin initially shifted the dose-response curve of phenylephrine to the right, with a significant increase in ED50 for phenylephrine from a control value of 102 to 759 ng/min on day 1 of terazosin (P < 0.001). The mean Kd of terazosin was estimated as 11 +/- 15 nM in the first few days of treatment. This study demonstrates that pharmacological tolerance to the alpha 1-adrenoceptor blocking action of terazosin occurs in man and may be responsible for loss in efficacy with chronic therapy [2].