Effect of tolvaptan on acute heart failure with hyponatremia – A randomized, double blind, controlled clinical trial

OBJECTIVES: To assess the efficacy of tolvaptan in acute heart failure with hyponatremia using a randomized double-blinded placebo-controlled study design. BACKGROUND: Tolvaptan is a selective vasopressin receptor 2 antagonist. There are no published clinical trials on the utility of tolvaptan in acute heart failure with hyponatremia in the Indian population. METHODS: After screening and informed consent, 51 HF patients with hyponatremia were randomized using computer-generated randomization sequence to receive placebo or 15mg of tolvaptan for 5 days along with conventional medical therapy. The patient's perception of dyspnea using Likert score and the plasma sodium was measured at baseline and for the next 4 days. RESULTS: There was a mean improvement in sodium concentration by 5mEq/L (p=0.001) in patients receiving tolvaptan, whereas no significant improvement was seen in the placebo group (p=0.33). Significant improvement in Likert score was observed in both the groups (p=0.001), even though there was no difference between both the groups. Dry mouth and thirst were the most commonly occurring adverse effects observed in both the groups. There were no significant hemodynamic changes with tolvaptan therapy. CONCLUSION: Tolvaptan at a dose of 15mg is effective in reversing hyponatremia in acute heart failure and may be a suitable option in these patients.