Prazosin

**Semantic type:** Organic Chemical|Pharmacologic Substance

**Definition:** A synthetic piperazine derivative and an alpha-1 adrenergic receptor inhibitor used primarily as an anti-hypertensive. Prazosin's effects are most pronounced in the large resistance vessels (i.e. arterioles) and result in a decrease in total systemic vascular resistance (SVR) without a rebound or reflex tachycardia. To a lesser extent, this agent also decreases the tone of the bladder sphincter, thereby allowing the opening of the bladder into the urethra and thus relieving the urinary conditions associated with benign prostatic hypertrophy.

**Synonyms:** - 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-furanylcarbonyl)piperazine - 2-[4-(2-furoyl)piperazin-1-yl]-4-amino-6,7-dimethoxyquinazoline - Furazosin - PRAZOSIN