Vasopressin

Category: peptide

Aliases: AVP, Arginine vasopressin, Antidiuretic hormone, ADH, Pitressin

Pharmacological Mechanism

Posterior-pituitary peptide differing from oxytocin by two residues (Phe-3 + Arg-8 vs Ile-3 + Leu-8). Activates V1a (vascular smooth muscle → vasoconstriction), V1b (pituitary → ACTH release), and V2 (renal collecting-duct → aquaporin-2 insertion → antidiuresis). Rapidly inactivated by peptidases — IV infusion required for vasopressor use.

Half-Life (t½)

IV: 0.4h

Target Organ Systems