ATC Group: H01B Posterior pituitary lobe hormones

Carbetocin selectively binds to oxytocin receptors in the smooth muscle of the uterus, stimulates rhythmic contractions of the uterus, increases the frequency of existing contractions, and raises the tone of the uterus musculature.

Desmopressin is a structural analogue of vasopressin in which the antidiuretic activity has been enhanced by the order of 10, while the vasopressor effect has been reduced by the order of 1500. The clinical advantage of this highly changed ratio of antidiuretic to vasopressor effect is that clinically active antidiuretic doses are far below the threshold for a vasopressor effect.

Oxytocin is a cyclic nonapeptide that is obtained by chemical synthesis. This synthetic form is identical to the natural hormone that is stored in the posterior pituitary and released into the systemic circulation in response to suckling and labour.

Terlipressin inhibits portal hypertension with simultaneous reduction of blood circulation in portal vessels. Terlipressin contracts smooth oesophageal muscle with consecutive compression of oesophageal varices.

The antidiuretic action of vasopressin is ascribed to increase in reabsorption of water by the renal tubules. Vasopressin can cause contraction of smooth muscle of the gastrointestinal tract, gall bladder, urinary bladder and all parts of the vascular bed, especially the capillaries, small arterioles and venules with less effect on the smooth musculature of the large veins. The direct effect on the contractile elements is neither antagonised by adrenergic blocking agents nor prevented by vascular denervation.