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Effect of Weight and/or Obesity on Ethambutol Drug Concentrations

Phase 4
Completed
Conditions
Obesity
Tuberculosis
Interventions
Registration Number
NCT01048697
Lead Sponsor
Texas Tech University Health Sciences Center
Brief Summary

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.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
18
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.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
EthambutolEthambutolAll 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)
Primary Outcome Measures
NameTimeMethod
Total Clearance of EthambutolBlood samples will be collected over a 24 hour period (0, 2, 6, 11, 18, and 24 hours)
Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

University of Texas Southwestern Medical Center

🇺🇸

Dallas, Texas, United States

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