Fractional Urate Excretion in Nonedematous Hyponatremia

NCT01425125 | Withdrawn

• 1 other identifier: 10029
• Study Type: interventional
• Target: N/A
• Locations: 1 country
• Sites: 1

Brief Summary

Hyponatremia, defined as a serum sodium \< 135 mmol/l, in patients without edema has undergone significant changes where it is now evident that even mild hyponatremia should be treated because of its association with symptoms, especially a fourfold increase in falls over the age of 65 years. There is an unresolved controversy over the relative prevalence of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and cerebral/renal salt wasting (C/RSW). Resolution of this diagnostic dilemma becomes urgent because of divergent therapeutic goals, to water-restrict in SIADH or to give salt and water supplementation in C/RSW. The dilemma is compounded by recent reports of C/RSW occurring in patients without cerebral disease, thus adding further confusion in defining the relative prevalence of both syndromes. Because of overlapping laboratory and clinical findings in both syndromes, only differences in the state of extracellular volume differentiates one syndrome from the other, being high normal to increased in SIADH and decreased in C/RSW. The investigators have used fractional excretion (FE) of urate to categorize patients with hyponatremia. The increased FEurate that is observed in hyponatremic patients with SIADH and C/RSW can be used to differentiate both syndromes by correcting the hyponatremia and determining whether FEurate normalizes as in SIADH or remains increased in C/RSW. The present studies have been designed to determine total body water by deuterium and extracellular water by sodium bromide in patients with nonedematous hyponatremia with normal and increased FEurate to differentiate more conclusively whether the patient has normal or decreased water volumes. The investigators will also correct serum sodium rapidly with judicious administration of hypertonic saline over approximately three days and determine whether FEurate normalizes as in SIADH or remains increased as in C/RSW. In another group of patients, The investigators have data to suggest that those with normal sodium and increased FEurate is consistent with C/RSW. The investigators intend to do the same water volume studies to determine whether an increased FEurate with normonatremia would have decreased total and extracellular water that these patients have C/RSW without the need to correct a prior hyponatremia.

Conditions

Cerebral Hyponatremia; SIADH; Cerebral Salt-wasting Syndrome; Reset Hypothalamic Osmostat

Keywords

nonedematous hyponatremia; fractional urate excretion

Outcome Measures

Primary Outcomes (1)

• Etiologic categorization of nonedematous hyponatremia

  We will attempt to categorize the etiology of nonedematous hyponatremia by the following parameters in decreasing order of importance, total and extracellular water determinations, fractional urate excretion, plasma renin and aldosterone levels, urinary sodium concentration and urine osmolality. We will also determine total and extracellular water in a group suspected of having renal salt wasting by virtue of having increased fractional urate excretion and normal serum sodium concentrations.

  2 years

Study Arms (1)

Tolvaptan in euvolemic hyponatremia

EXPERIMENTAL

This arm will test the effectiveness of tolvaptan in treating the hyponatremia of patients with euvolemic hyponatremia.

Drug: Tolvaptan in euvolemic hyponatremia

Interventions

Tolvaptan in euvolemic hyponatremia DRUG

This arm will test the effectiveness of tolvaptan in treating the hyponatremia of patients with euvolemic hyponatremia.

Also known as: oral tolvaptan (Samsca

Tolvaptan in euvolemic hyponatremia

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• \- Nonedematous hyponatremia with normal renal, adrenal and thyroid function. -Non-hyponatremia with increased fractional excretion of urate.

You may not qualify if:

• Subjects \< 18 years of age
• Pregnancy
• Serum creatinine \> 1.4 mg/dl

Sponsors & Collaborators

• NYU Langone Health: lead

Study Sites (1)

Winthrop-University Hospital

Mineola, New York, 11501, United States

Location

MeSH Terms

Conditions

Inappropriate ADH Syndrome

Interventions

Tolvaptan

Condition Hierarchy (Ancestors)

Pituitary Diseases; Hypothalamic Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Water-Electrolyte Imbalance; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases

Intervention Hierarchy (Ancestors)

Benzazepines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds

Study Officials

• John K Maesaka, MD

  Winthrop University Hospital

  PRINCIPAL INVESTIGATOR

• Louis J Imbriano, MD

  Winthrop University Hospital

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 25, 2011
• First Posted: August 29, 2011
• Study Start: November 1, 2011
• Primary Completion: December 1, 2014
• Study Completion: December 1, 2014
• Last Updated: February 6, 2019

Record last verified: 2019-02

Locations

US (1)