Effect of Weight and/or Obesity on Ethambutol Drug Concentrations

This study is designed to measure drug concentrations in the blood of healthy volunteers administered a single dose of ethambutol. Our hypothesis is that volunteers with a body mass index (BMI) 25-40 kg/m2 will remove ethambutol more quickly from the blood than leaner volunteers, and those with a BMI > 40 kg/m2 will have even greater clearance than those who are leaner.

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Key information

Conditions

Obesity Actinomycetales Infections Bacterial Infections Bacterial Infections and Mycoses Body Weight Gram-Positive Bacterial Infections Infections Mycobacterium Infections Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms Tuberculosis

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

University of Texas Southwestern Medical Center

Dallas, Texas, 75390, United States

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

Male and female volunteers, age 18 years of age or older, of all racial and ethnic origins. English and/or Spanish speaking volunteers are eligible to participate.
We are recruiting 6 normal weight (BMI <25 kg/m2), 6 obese (BMI 25-40 kg/m2), and 6 extremely obese (BMI > 40 kg/m2) for this study. Half of each group will be male, the other half will be female.

Exclusion criteria

Creatinine clearance < 70 ml/min as estimated by the Cockcroft-Gault equation.
Pregnant or nursing or unwilling to use a reliable contraception method during the study period. The effects of ethambutol on pregnancy are unknown. In addition, the metabolic changes that accompany pregnancy may alter the concentration-time profile of ethambutol, so that the pregnancy and post-partum state would be a confounding variable.
Abnormal liver function tests: transaminases >10 time the upper limit of normal, alkaline phosphatase > 5 time the upper limit of normal, total bilirubin >5 time the upper limit of normal.
History of allergy to ethambutol.
Ethambutol is contraindicated for any reason.
Suspected or documented mycobacterial infection.
History of gout.

Treatment and study plan

Ethambutol

Drug

All volunteers in each category will receive a single dose of oral ethambutol based on American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of American (ATS/CDC/IDSA) TB treatment guidelines.1 We will not use any doses higher than the maximum dose recommended for daily administration by the current ATS/CDC/IDSA TB guidelines (which use ideal body weight for dosing):

40-55kg: 800 mg (two 400 mg tablets) 56-75kg: 1,200 mg (three 400 mg tablets) 76-90kg: 1,600 mg (four 400 mg tablets) > 90 kg: No dosage recommendations so these volunteers will only receive 1,600 mg (four 400 mg tablets)

Other names: Myambutol

Primary outcomes

Total Clearance of Ethambutol

Time frame: Blood samples will be collected over a 24 hour period (0, 2, 6, 11, 18, and 24 hours)

Sponsors and collaborators

Lead sponsor

Texas Tech University Health Sciences Center

Other

Collaborators

National Center for Research Resources (NCRR)
University of Texas Southwestern Medical Center

Registry information

Official study title

Population Pharmacokinetics Analysis of Ethambutol in Overweight and Obese Volunteers

Important dates

Study start: 2010
Primary completion: 2010
Study completion: 2010
First posted: Jan 14, 2010
Registry last updated: Jan 24, 2013

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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