A Study to Assess the Efficacy, Safety and Pharmacokinetics of Intravenous Conivaptan (Vaprisol®) in Pediatric Subjects With Euvolemic or Hypervolemic Hyponatremia

A 3:1 randomization between conivaptan and placebo will be implemented and randomization will be further stratified in a 1:1:2 ratio for age groups: 2-5 years, 6-10 years, and 11-17 years. Subjects will need to remain hospitalized for the 48-hour Treatment Period through Hour 96 (Day 4). There will be a follow-up safety visit on Day 9 or day of hospital discharge, whichever occurs first. There is a final follow-up phone call at Day 32 to assess if any serious adverse events have occurred since hospital discharge.