tolvaptan brands

Molecular formula: C26H25ClN2O3

Tolvaptan is a selective and competitive arginine vasopressin receptor 2 antagonist. Vasopressin acts on the V2 receptors found in the walls of the vasculature and luminal membranes of renal collecting ducts. By blocking V2 receptors in the renal collecting ducts, aquaporins do not insert themselves into the walls thus preventing water absorption. This action ultimately results in an increase in urine volume, decrease urine osmolality, and increase electrolyte-free water clearance to reduce intravascular volume and an increase serum sodium levels. Tolvaptan is especially useful for heart failure patients as they have higher serum levels of vasopressin. Tolvaptan is a vasopressin antagonist that blocks the binding of arginine vasopressin (AVP) at the V2 receptors of the distal portions of the nephron. Animal pharmacology studies indicated that tolvaptan should increase excretion of water without increasing excretion of electrolytes (aquaresis) and thus offer a means of correcting serum sodium concentration by inducing excretion of water without loss of serum electrolytes. Tolvaptan is about 29 times more selective for V2 receptors than for V1a receptors with virtually no binding to V1b receptors. Tolvaptan is a selective vasopressin V2-receptor antagonist with an affinity for the V2-receptor that is 1.8 times that of native arginine vasopressin (AVP). Tolvaptan affinity for the V2-receptor is 29 times greater than for the V1a-receptor. When taken orally, 15 to 60 mg doses of tolvaptan antagonize the effect of vasopressin and cause an increase in urine water excretion that results in an increase in free water clearance (aquaresis), a decrease in urine osmolality, and a resulting increase in serum sodium concentrations. Urinary excretion of sodium and potassium and plasma potassium concentrations are not significantly changed. Tolvaptan metabolites have no or weak antagonist activity for human V2-receptors compared with tolvaptan. Plasma concentrations of native AVP may increase (avg. 2-9 pg/mL) with tolvaptan administration.

Source: PubChem (NCBI) · compound 216237