What is "alpha blocker"

n. any of various drugs that block alpha-adrenergic receptors; used in treating benign prostatic hyperplasia; relaxes the muscles of the prostate and bladder [syn: alpha-blocker, alpha-adrenergic blocker, alpha-adrenergic blocking agent]

Alpha-blockers or α-blockers are pharmacological agents that act as neutral antagonists or inverse agonists of α-adrenergic receptors (α-adrenoceptors).