Role of Midodrine and Tolvaptan in Patients With Cirrhosis With Refractory or Recurrent Ascites

Overview

The development of ascites in the natural history of cirrhosis heralds a worsening of the prognosis to 50% survival at 2 years, and this deteriorates to 30-50% at 1 year when the ascites becomes refractory to medical therapy. Hemodynamic alterations and their relation to neurohumoral systems are essential in pathophysiology of ascites formation. The theory that best explain the ascites formation and sodium retention in cirrhotics is portal hypertension leading to splanchnic arterial vasodilatation leading to underfilling of arterial circulation which is sensed by the arterial and the cardiopulmonary receptors leading to sympathetic nervous system activation and activation of the anti-natriuretic factors (RAAS and arginine vasopressin), resulting in sodium and water retention. The therapeutic options available for patients with refractory ascites are serial therapeutic paracentesis, liver transplantation and transjugular intrahepatic portosystemic shunts.Vasopressin V2 receptor antagonists antagonize the antidiuretic effects of vasopressin at the V2 receptor located in the renal collecting duct, they increase free water clearance, and thus may be helpful in mobilizing excess water in conditions associated with water retention including cirrhosis. The use of V2 receptor antagonists in cirrhosis with ascites has been shown to be safe and efficacious. Midodrine, an alpha adreno receptor agonist by causing splanchnic vasoconstriction has been used in hepatorenal syndrome (HRS) and for control of ascites in patients with refractory or recurrent ascites. It is possible that vasoconstrictors and aquaretics (V2 receptor antagonists) by acting at different sites in combination may reverse some of the pathogenic events that results in refractory or recurrent ascites.There are no reports on the use of combination of midodrine and tolvaptan in the patients with cirrhosis with ascites. Therefore, we plan to study the role of midodrine, tolvaptan and their combination on systemic hemodynamics, renal functions and control of ascites in patients with cirrhosis and refractory or recurrent ascites.