Comparison of two dosing methods for immediate administration of tolvaptan in acute decompensated heart failure

The clinical dosing method for tolvaptan in patients with acute heart failure (HF) is still unclear. We aimed to compare the differences in clinical effect between two dosing regimens: once-daily 7.5mg and twice-daily 3.75mg.In this randomized trial, tolvaptan was administered within 12h from hospital admission. The primary outcome was the serial change in congestion scores measured every day from enrollment until dosing day 7. Outcomes including safety parameters were also evaluated.The subjects were assigned to either the once-daily 7.5mg dosing regimen (N=15) or the twice-daily 3.75mg dosing regimen (N=16). The time-course changes in body weight, serum sodium and creatinine levels, systolic blood pressure, daily urine output, and congestion scores were similar between the two groups. In the twice-daily 3.75mg dosing group, the serum sodium levels on days 3 and 4 were significantly (p0.05) increased compared with those on day 1. The congestion scores significantly (p0.05) decreased from day 2 to day 7 in both groups compared with those on day 1. However, the difference in the serial change in the congestion scores did not reach statistical significance.Our present results suggest that the early administration of tolvaptan within 12h after hospital admission significantly improved congestion from the first day after administration by either dosing regimen, i.e. once-daily 7.5mg or twice-daily 3.75mg in patients with acute HF.