Ornipressin (ornithine-8-vasopressin, POR-8), is a synthetic vasopressin analogue. Ornipressin produces vasoconstriction via vasopressin V1A receptor-mediated vascular smooth muscle cell contraction. Ornipressin is used to control bleeding in surgical practice. It was introduced in 1971, and approved for use in Germany, Switzerland, New Zealand and Australia.

Mozavaptan hydrochloride was approved by Pharmaceuticals and Medical Devices Agency of Japan (PMDA) on July 26, 2006. It was developed and marketed as Physuline® by Otsuka in Japan. Mozavaptan hydrochloride is a vasopressin receptor antagonist. It is indicated for the treatment of hyponatremia due to excessive fluid retention when restriction of fluid intake is ineffective. Physuline® is available as film-coated tablet for oral use, containing 30 mg of Mozavaptan hydrochloride. The recommended dose is one tablet (30 mg) once daily after a meal.

Terlipressin (Glypressin) is indicated for the treatment of bleeding oesophageal varices and in some countries for the treatment of hepatorenal syndrome type 1. It is a prodrug and is converted to the lysine vasopressin in the circulation after the N-triglycyl residue is cleaved by endothelial peptidases. This results in a ‘slow release’ of the vasoactive lysine vasopressin. Terlipressin exerts its action by activating V1a, V1b and V2 vasopressin receptors. On September 14, 2022, the FDA granted approval to terlipressin (Terlivaz) for the treatment of adults hospitalized with hepatorenal syndrome with rapid reduction in kidney function (HRS-1). Prior to the approval, no approved treatment for this condition existed in the United States.

More than a century ago, Sir Henry Dale demonstrated that a component of the pituitary causes contractions of the mammalian uterus, hence his coining the term “oxytocic,” derived from the Greek for “quick birth,” for its activity. The discovery that a component of the pituitary causes milk secretion followed within a few years. By 1930, oxytocin was separated from vasopressin into pitocin and pitressin, respectively, at Parke Davis and made available for research. That a single peptide was responsible for these uterine and mammary actions was definitively confirmed upon the sequencing and synthesis of the peptide, 9 amino acids in length. Vincent du Vigneaud was awarded a Nobel Prize for this work. Oxytocin is indicated for the initiation or improvement of uterine contractions, where this is desirable and considered suitable for reasons of fetal or maternal concern, in order to achieve vaginal delivery. Oxytocin is indicated to produce uterine contractions during the third stage of labor and to control postpartum bleeding or hemorrhage. Uterine motility depends on the formation of the contractile protein actomyosin under the influence of the Ca2+- dependent phosphorylating enzyme myosin light-chain kinase. Oxytocin promotes contractions by increasing the intracellular Ca2+. Oxytocin has specific receptors in the myometrium and the receptor concentration increases greatly during pregnancy, reaching a maximum in early labor at term. The Oxytocin receptor is a typical class I G protein-coupled receptor that is primarily coupled via G(q) proteins to phospholipase C-beta. The high-affinity receptor state requires both Mg(2+) and cholesterol, which probably function as allosteric modulators. The agonist-binding region of the receptor has been characterized by mutagenesis and molecular modeling and is different from the antagonist binding site. The function and physiological regulation of the Oxytocin system is strongly steroid dependent.

Lypressin is synthetic analog of porcine antidiuretic hormone vasopressin. Itis a cyclic nonapeptide that differs from Arg-vasopressin by one amino acid, containing Lys at residue 8 instead of Arg. Lypressin-containing nasal spray was used to treat diabetes insipidus, but its marketing by Sandoz (Novartis) was discontinued.