Vaptans for Ascites – Chances and Risks

Ascites is a common complication of cirrhosis. The presence of ascites is associated with significant morbidity and mortality. Traditional treatments of ascites with diuretics and repeat large-volume paracenteses have their limitations. Definitive treatments of ascites such as the insertion of a trans-jugular intrahepatic portosystemic shunt or liver transplantation are available to suitably selected patients. The development of vasopressin V2 receptor antagonists or vaptans as a treatment for hyponatremia associated with ascites has proven to be a welcoming addition to the management of these patients. Six vaptans have been assessed and all have been shown to be effective in correcting hyponatremia. Tolvaptan, conivaptan and moxivaptan are approved worldwide for clinical use for the correction of hyponatremia from any etiology. Satavaptan and tolvaptan have also been shown to improve the quality of life of patients once hyponatremia is corrected. The sodium-correcting effect of the vaptans can only be maintained while patients are taking it. Satavaptan, tolvaptan and M0002 may also have an ascites-reducing effect. Satavaptan has been studied for 52 weeks in several phase III trials and renal impairment and hyperkalemia seem to be two consistent side effects. All of the other vaptans have only been studied for less than 30 days. Therefore, the full risks or benefits related to the other vaptans are unknown. Until the long-term results of the other vaptans are known, it is prudent to start with a low dose and titrate upwards to find the appropriate dose for the desired effect.