Phenoxybenzamine

**Semantic type:** Hazardous or Poisonous Substance|Pharmacologic Substance

**Definition:** A synthetic, dibenzamine alpha adrenergic antagonist with antihypertensive and vasodilatory properties. Phenoxybenzamine non-selectively and irreversibly blocks the postsynaptic alpha-adrenergic receptor in smooth muscle, thereby preventing vasoconstriction, relieving vasospasms, and decreasing peripheral resistance. Reflex tachycardia may occur and may be enhanced by blockade of alpha-2 receptors which enhances norepinephrine release. Phenoxybenzamine is reasonably anticipated to be a human carcinogen.

**Synonyms:** - N-(2-chloroethyl)-N-(1-methyl-2-phenoxyethyl)-benzenemethanamine - PHENOXYBENZAMINE