Phase III Study of Tolvaptan Tablet to Treat Cirrhosis Ascites

To evaluate the efficacy and safety of Tolvaptan 7.5mg and 15mg in treatment of patients with cirrhosis ascites who fail to response adequately to treatment with common diuretics.

For symptoms of fluid retention due to liver diseases (ascites and/or lower extremity edema, i.e. hepatic edema), treatment generally starts with bed rest and a low-salt diet. Aldosterone antagonists and loop diuretics are commonly used diuretics in the treatment of fluid retention due to liver diseases. In aldosterone antagonists' therapy, nevertheless, hyperkalemia is frequently reported, slow onset of action and dose escalation needed also impair its effect. If aldosterone antagonists' therapy is ineffective, loop diuretics as strong diuretics are usually added up. However, Dose escalation of loop diuretics also boost the occurrence of hyponatremia and hypokalemia, and combination of the two drugs provided fastest onset of effectiveness with less adverse events. While, because both diuretics can cause sodium lose which is difficult to prevent and treat, hyponatremia is easy to occur. The combination of aldosterone antagonists and K-sparing diuretics reduces the occurrence of hypokalemia but have little effect on the prevention and treatment of hyponatremia. In addition, there are still some patients who are resistent to loop diuretics or intolerant of an effective diuretic dosage due to adverse events. Tolvaptan increases the excretion of electrolyte-free water (aquaretic) without changing electrolytes excretion by inhibiting the water reabsorption of collecting duct in kidney. It is demonstrated that Tolvaptan increased urine volume without impairing renal function.