A Trial of Tolvaptan in Children and Adolescent Subjects With Euvolemic and Hypervolemic Hyponatremia

Inclusion criteria

• . Male and female subjects ≥ 4 years of age (or per local Health Authority age restriction) to \< 18 years old and ≥ 10kg
• . Subjects hospitalized with euvolemic or hypervolemic hyponatremia resistant to initial standard background therapy (including fluid restriction and excluding a vasopressin antagonist) and who are deemed by the investigator as likely to benefit from a therapy that raises serum sodium levels
• . Persistent euvolemic or hypervolemic hyponatremia defined as being documented as present for at least 48 hours, evidenced by at least 2 serum sodium assessments \< 130 mmol/L drawn at least 12 hours apart (these values can be documented using historical values previously obtained per standard of care); a third (STAT) serum sodium assessment \< 130 mmol/L, which will serve as the baseline value for efficacy endpoints, is to be obtained within 2-4 hours prior to the final trial qualification and the first dose of IMP
• . Ability to swallow tablets
• . Ability to maintain adequate fluid intake whether orally or via IV support with adequate monitoring
• . Ability to comply with all requirements of the trial
• . Trial-specific written informed consent/assent obtained from a parent/legal guardian or legally acceptable representative, as applicable per age of subject or local laws, prior to the initiation of any protocol required procedures. In addition, the subject as required by local laws must provide informed assent at Screening and must be able to understand that he or she can withdraw from the trial at any time.