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Completed

NCT Number: NCT02111200

Comparative Efficacy of Phenylbutyrate (PBA) vs. Benzoate in Urea Cycle Disorders

The investigators will study and compare how effectively sodium phenylbutyrate, sodium benzoate, and a combination of the two, help excrete nitrogen in healthy volunteers. Subject participation will require three, separate, four-day study periods at least one week apart. During one study period (also called a treatment arm), subjects will take sodium phenylbutyrate; during another they will take sodium benzoate; during another they will take a combination of the two medications.

We expect to find that phenylbutyrate is more effective at removing nitrogen than benzoate or a combination of the two.

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Key information

Conditions

Urea Cycle Disorders, Inborn Amino Acid Metabolism, Inborn Errors Brain Diseases Brain Diseases, Metabolic Brain Diseases, Metabolic, Inborn Central Nervous System Diseases Congenital, Hereditary, and Neonatal Diseases and Abnormalities Genetic Diseases, Inborn Metabolic Diseases Metabolism, Inborn Errors Nervous System Diseases Nutritional and Metabolic Diseases

Age range

18 year–64 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Children's Nutrition Research Center/Baylor College of Medicine

Houston, Texas, 77030, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Healthy volunteers

Exclusion criteria

  • Subjects with (a) a history of frequent dietary protein intolerance, (b) a history of chronic or acute liver diseases which may result in altered hepatic synthetic capacity (e.g., hepatitis), (c) acute or chronic disease or on medications that in the opinion of the clinical investigators will interfere with the measurements (e.g., drugs which may have hepatotoxicity as potential side effects), (d) a physical disability that will interfere with their ability to either conform to the dietary regimes or undergo the isotopic infusions, (e) pregnancy or recent (<6 months)/current lactation, (f) intercurrent evidence of significant hyperammonemia (more than 100 µmol/L), (g) any clinical abnormality of Grade 3 or greater according to the Common Terminology Criteria for Adverse Events v.4.0 (CTCAE), (h) any condition(s) not covered by the CTCAE, or (i) a severe or life-threatening toxicity at screening, will be excluded from the study. Subjects taking ammonia scavenger medications will not be enrolled.

Treatment and study plan

Sodium Benzoate

Drug

Subjects will be instructed to take the study medication with meals (08:00 breakfast; 13:00 lunch; 19:00 dinner) for 3 days.

Sodium Phenylbutyrate

Drug

Subjects will be instructed to take the study medication with meals (08:00 breakfast; 13:00 lunch; 19:00 dinner) for 3 days.

Other names: Buphenyl (tm)

Primary outcomes

  1. Urinary Hippuric Acid

    Time frame: 4 days per arm

    The objective of this protocol is to directly compare the efficacy of benzoate, phenylbutyrate and a combination of the two, to conjugate nitrogenous compounds in healthy volunteers. The nitrogenous compound of interest in each arm would be based on the medication used. This would be hippuric acid in the benzoate arm, phenylacetylglutamine in the phenylbutyrate arm, and hippuric acid AND phenylacetylglutamine in the MIX arm. The mean hippuric acid levels in the phenylbutyrate arm would thus be 0.

  2. Urinary PAGN Excretion

    Time frame: 4 days per arm

    The objective of this protocol is to directly compare the efficacy of benzoate, phenylbutyrate and a combination of the two, to conjugate nitrogenous compounds in healthy volunteers. The nitrogenous compound of interest in each arm would be based on the medication used. This would be hippuric acid in the benzoate arm, phenylacetylglutamine in the phenylbutyrate arm, and hippuric acid AND phenylacetylglutamine in the MIX arm. The mean phenylacetylglutamine levels in the benzoate arm would thus be 0.

  3. Total Nitrogen as a Conjugate of the Drug

    Time frame: 4 days per arm

    The objective of this protocol is to directly compare the efficacy of benzoate, phenylbutyrate and a combination of the two, to conjugate nitrogenous compounds in healthy volunteers. The nitrogenous compound of interest in each arm would be based on the medication used. This would be hippuric acid in the benzoate arm, phenylacetylglutamine in the phenylbutyrate arm, and hippuric acid AND phenylacetylglutamine in the MIX arm.

Sponsors and collaborators

Lead sponsor

Baylor College of Medicine

Other

Registry information

Official study title

Comparative Efficacy of Phenylbutyrate vs. Benzoate in Urea Cycle Disorders

Acronym: BPA/Benzoate

Important dates

Study start
2014
Primary completion
2015
Study completion
2015
First posted
Apr 11, 2014
Registry last updated
Jan 9, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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