International, Multicenter, Study of One-year, Open-label, Titrated Oral Tolvaptan Tablet Administration in Patients With Chronic Hyponatremia

International, Multicenter, Study of One-year, Open-label, Titrated Oral Tolvaptan Tablet Administration in Patients With Chronic Hyponatremia: Extension to Studies 156-02-235 and 156-03-238 to Assess One-year Safety

This study will assess the safety of long-term tolvaptan use in patients previously enrolled in shorter-term Phase 3 studies and gather information on the natural history of hyponatremia in the context of tolvaptan therapy and underlying disease states.

Inclusion Criteria:

1. Age greater than or equal to 18 years.
2. Ability to provide informed consent or assent.
3. Prior successful participation in a tolvaptan hyponatremia trial termination with evidence of continued need or desire for therapy.

Exclusion Criteria:

• A current medical condition where long-term treatment with an aquaretic agent may present an undue risk to the patient.
• Hyponatremia which is acute, reversible, artifactual or due to conditions not associated with vasopressin excess or likely to respond to aquaretic therapy.
• Hyponatremia due to reversible medical condition or therapy
• Conditions associated with an independent imminent risk of morbidity and mortality
• Conditions which confound the assessment of endpoints.