Effect of the oral vasopressin receptor antagonist tolvaptan on congestive cardiac failure in a child with restrictive cardiomyopathy.

Tolvaptan, an oral vasopressin receptor antagonist, was administered to a 6-year-old boy with advanced congestive cardiac failure due to restrictive cardiomyopathy. Slow up-titration of the tolvaptan improved the loop diuretic-resistant congestive cardiac failure without hypernatraemia, deterioration of vital signs, and significant complications. Tolvaptan could be useful and safe for children with severe congestive cardiac failure. It is necessary to accumulate clinical data on tolvaptan administration in children in order to determine the optimal method of administration.