Vasopressin V2 Receptor Blockade With Tolvaptan Versus Fluid Restriction in the Treatment of Hyponatremia

Tolvaptan appears to be more effective than fluid restriction at correcting hyponatremia in hospitalized subjects, without an increase in adverse events.

Abstract

Hyponatremia is common and is associated with a poor prognosis. Traditional management with fluid restriction is difficult to maintain, and it is often ineffective. The objective of this study was to determine the effect of tolvaptan versus fluid restriction on serum sodium concentration. The study was a prospective, multicenter, randomized, active-controlled, open-label trial. Twenty-eight hospitalized subjects with serum sodium 135 mmol/L or a > or =10% increase from baseline. At the last inpatient visit, serum sodium had increased by 5.7 +/- 3.2 mmol/L in the tolvaptan group and 1.0 +/- 4.7 mmol/L in the fluid restriction group (p = 0.0065). No differences in adverse events were observed between the groups. In conclusion, tolvaptan appears to be more effective than fluid restriction at correcting hyponatremia in hospitalized subjects, without an increase in adverse events.