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Effects of Tolvaptan in Healthy Adults

NCT01973140 · Status: COMPLETED · Phase: PHASE4 · Type: INTERVENTIONAL · Enrollment: 17

Last updated 2016-09-28

No results posted yet for this study

Summary

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.

Conditions

  • Healthy

Interventions

DRUG

Tolvaptan

Adult male volunteers will be given a given a 60mg or a 30 mg dose of tolvaptan. Blood and urine samples will be collected at specified time points for the next 24 hours.

DRUG

Hypertonic saline infusion

A week after the first intervention(tolvaptan), the subjects will undergo a hypertonic saline infusion for 6 hours. Blood and urine samples will be collected at specified time points until 4hour hours after the infusion.

Sponsors & Collaborators

Principal Investigators

  • Gary L Robertson, MD · Northwestern University

Study Design

Allocation
NA
Masking
NONE
Model
SINGLE_GROUP

Eligibility

Min Age
21 Years
Max Age
55 Years
Sex
MALE
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2013-11-30
Primary Completion
2015-12-31
Completion
2016-03-31

Countries

  • United States

Study Locations

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Entities

Companies

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT01973140 on ClinicalTrials.gov