Core Safety Follow-up Component~• For all participants: To evaluate the post-treatment safety follow-up of children and adolescent participants with dilutional (euvolemic or hypervolemic) hyponatremia who have previously participated in a tolvaptan hyponatremia trial.~Optional Tolvaptan Treatment Component~• For participants who receive optional tolvaptan treatment: To demonstrate that tolvaptan safely and effectively achieves and maintains increased serum sodium concentrations in children and adolescent participants with dilutional (euvolemic or hypervolemic) hyponatremia when used for both multiple short-term treatments, and/or longer chronic treatments.
The objective of this trial was to provide 6 months of safety follow-up for children and adolescents with dilutional (euvolemic or hypervolemic) hyponatremia who had previously participated in a tolvaptan hyponatremia trial and to assess the efficacy of tolvaptan in increasing serum sodium for those participants who received optional continuing tolvaptan treatment of variable duration (up to 6 months).