Serum sodium concentrations over the course of the trial are shown in Figure 3.
Within 8 hours after the first administration of tolvaptan, the serum sodium concentrations were significantly
higher in the tolvaptan group than in the placebo group for both the total patient population and the subgroups stratified according to the degree of hyponatremia at baseline.
This statistical superiority was maintained at all subsequent visits during the study period within all stratification
subgroups.
The serum sodium concentration approached the normal range more rapidly in the tolvaptan group than in the placebo group.
During the follow-up week after discontinuation of the study drug, there was no statistical difference in the decline in serum sodium concentrations between the two groups.