Effects of Tolvaptan in Healthy Adults
Public ClinicalTrials.gov record NCT01973140. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Variation in the Aquaretic Efficacy of Tolvaptan in Healthy Adults
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Tolvaptan is one of new class of medications approved for treatment of low blood sodium (hyponatremia). It works by interfering with the effect of the antidiuretic hormone, vasopressin, thereby increasing urine output and decreasing body water. However, the magnitude of these effects vary from person to person. Thus, the efficacy of tolvaptan is less reliable than an infusion of a concentrated salt solution for emergency, short term treatment of hyponatremia. This study is designed to test 3 hypotheses about the variable efficacy of tolvaptan. 1. The variable effect on urine output is due to individual differences in blood vasopressin which counteracts the effects of tolvaptan. 2. The differences in blood vasopressin are due to individual differences in the amount secreted in response to a rise in blood sodium. 3. The variable effect on blood sodium is due mainly to the variable effect on urine output and can be corrected by maintaining water intake below urine output. The study has 2 parts and will be performed in 12 healthy adult males. 1. Six subjects will receive tolvaptan at a dose of 60 mg by mouth and six subjects will receive tolvaptan at 30 mg by mouth. Blood and urine will be collected hourly for 6 hours and water will be ingested in prescribed amounts. For the next 16 hours, subjects will drink at will and blood and urine will be collected 4 more times. 2. One week later, the same subjects will receive a concentrated salt solution (3% saline) by vein for 6 hours. During this time, blood and urine will be collected hourly but drinking will not be permitted. For the next 4 hours, subjects will be allowed to drink at will while blood and urine are collected twice more. The volume, concentration and creatinine content of each urine will be determined. Blood will be analyzed for sodium, vasopressin and, in the first study, tolvaptan.
Study identification
- NCT ID
- NCT01973140
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 4
- Enrollment
- 17 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 21 Years to 55 Years
- Sex
- Male
- Healthy volunteers
- Accepts healthy volunteers
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Oct 31, 2013
- Primary completion
- Nov 30, 2015
- Completion
- Feb 29, 2016
- Last update posted
- Sep 27, 2016
2013 – 2016
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Clinical Research Unit Northwestern Memorial Hospital | Chicago | Illinois | 60611 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT01973140, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Sep 27, 2016 · Synced Sep 2, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT01973140 live on ClinicalTrials.gov.