Short-Term Effects of Tolvaptan in Patients with Severe Chronic Kidney Disease and Heart Failure with Fluid Overload

Background: In patients with severe chronic kidney disease (CKD), congestive heart failure (CHF), diuretic resistance, and hyponatremia represent treatment impediments. Tolvaptan, a diuretic with a new mechanism of action, selectively binds to vasopressin V2 receptor and inhibits reabsorption of water. Its effects on heart failure (HF) have been proven, but its benefit to patients with CKD has not been confirmed. In this study, we examined the effects of tolvaptan on patients with severe CKD and HF. Materials and methods: We analyzed patients with stage 5 CKD and CHF that was resistant to existing diuretics. Urine volume, urine osmolality, body weight, sodium (Na) level, and B-type natriuretic peptide (BNP) were the main effective endpoints and analyzed laboratory data. Results: There was no clinically significant hypernatremia. However, free water clearance did show an increasing tendency. Urine volume increased significantly (P = 0.026), while body weight (P ＜ 0.01) and BNP (P = 0.006) decreased significantly. There were no significant changes in serum creatinine (Cr) level or adverse events. Conclusion: Tolvaptan has a diuretic effect in patients with severe CKD and CHF but does not cause clinically significant hypernatremia or adverse effects on renal function. Adding tolvaptan to conventional loop diuretic can enhance diuresis.