Samsca Post Marketing Surveillance Study

Study Overview
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Brief Summary
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This Post-Marketing Surveillance will be conducted in accordance with the local regulation of New Drug Re-examination. The surveillance will be conducted for 6 years of the re-examination period (01Sep2011 31Aug2017). Each subject will be observed at least for 4 days during the surveillance period.

Detailed Description
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This study will be conducted as a prospective, single-arm, multicenter study. Findings on examination, diagnosis, opinions and observations implemented as per general medical practice during the observational period will be documented in the case report forms by the investigators or responsible staffs at the institution since the surveillance is an observational study.

Official Title
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Post Marketing Surveillance Study of Safety and Efficacy of Samsca® Tablets Under the New Drug Re-Examination

Conditions
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Hypervolemic and Euvolemic Hyponatremia

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects must meet all of the following inclusion criteria to be eligible for enrollment into the study : Patients who have hyponatremia in euvolemic or hypervolemic states, defined as serum sodium level < 125 mEq/L or hyponatremia that is symptomatic and has resisted correction with fluid restriction Patients who are prescribed Samsca® treatment as per investigator's medical judgment Patients who gave written authorization to use their personal and health data Patients starting Samsca® treatment after agreement is in place Investigators will refer to the product market authorization (label) for inclusion criteria. Exclusion Criteria: Subjects presenting with any of the following will not be included in the study: Patients who have been treated with Samsca® Patients with known or suspected hypersensitivity to tolvaptan or to any ingredient of the drug Patients requiring urgent intervention to raise serum sodium acutely. Inability of the patient to sense or appropriately respond to thirst. Hypovolemic hyponatremia Concomitant use of strong CYP3A inhibitors Anuric patients Volume depletion patients Hypernatremia patients Women who are pregnant or possibly pregnant and lactation Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption Investigators will refer to the product market authorization (label) for exclusion criteria.
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Safety Measure | Adverse Events (AEs) | 4days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of the Serum Sodium Level(mEq/L) at the First Visit and Day 4 After the First Visit | In the efficacy analysis set, mean change of serum sodium level (mEq/L)on the 4th day compared to the first visit | Follow-up at least 4 days after first Samsca® dose |