Tulvaptan

Tulvaptan is not a widely recognized pharmaceutical product name. It most likely refers to tolvaptan, a vasopressin V2 receptor antagonist used in the management of certain forms of hyponatremia and, in some markets, autosomal dominant polycystic kidney disease (ADPKD).

Tolvaptan works by blocking the vasopressin V2 receptors in the kidney, promoting aquaresis—excretion of free water without substantial loss of electrolytes. By increasing free water clearance, it can raise serum sodium in patients with hyponatremia, such as those with SIADH, congestive heart failure, or cirrhosis. In ADPKD, tolvaptan slows the progression of cyst growth and decline in kidney function in some adults, delaying the need for dialysis.

The drug is typically administered orally and is prescribed with careful patient selection and monitoring. Because tolvaptan is metabolized mainly by CYP3A enzymes, concurrent strong CYP3A inhibitors or inducers can affect its levels and safety. Dosing is tailored to the indication and patient response, with close monitoring of sodium levels to avoid overly rapid correction and of liver function due to potential hepatotoxicity.

Safety considerations include a risk of excessive correction of sodium, thirst and polyuria, nocturia, dry mouth, and potential liver injury. Tolvaptan carries a boxed warning for hepatotoxicity in some indications and is subject to regulatory monitoring (REMS in certain markets). It is available by prescription only and is not approved for all hyponatremia etiologies in every jurisdiction.

See also: vasopressin receptor antagonists; conivaptan.