Effect of CYP2B6 genotype and efavirenz on the disposition and pharmacodynamic of methadone and tizanidine in healthy volunteers

Z
Zeruesenay Desta

Primary Investigator

Effect of CYP2B6 genotype and efavirenz on the disposition and pharmacodynamic of methadone and tizanidine in healthy volunteers
Enrolling By Invitation
18 years - 65 years
All
Phase N/A
72 participants needed
1 Location

Brief description of study

What is this study about?
The purpose of this study is to see how efavirenz, a widely used medication to treat HIV infection, interacts with methadone (a medication used to treat addiction problems and pain) and tizanidine (a medication used to relax muscle) when taken at the same time. 
 
The information learned in this study will help to inform doctors as to how to appropriately adjust doses of efavirenz, methadone and tizanidine to improve health outcomes and long-term treatment success for HIV patients.
 
Who can participate?
Healthy adults who are able to refrain from taking certain medications during the study period.

Detailed description of study

What happens during study participation?
1) Attend a short Screening visit to verify health and eligibility.
2) If you are eligible and choose to participate, you will be asked to do the following:
  • Take three FDA-approved medications
  • Have blood and urine collected
  • Stay overnight for two inpatient visits (meals will be provided)
  • Attend 4 brief outpatient visits
  • Keep a medication diary for 16 days of at-home study medication
  • All study visits will be performed at the Indiana Clinical Research Center (ICRC) at Indiana University Hospital in Indianapolis, IN
Incentive/compensation
  • Participants may earn $1000 for completing all of the study requirements
 
Additional information
Study title:  Effect of CYP2B6 genotype and efavirenz on the disposition and pharmacodynamic of methadone and tizanidine in healthy volunteers
 
This study is being conducted by Dr. Zeruesenay Desta, Professor of Medicine, Division of Clinical Pharmacology/Department of medicine Indiana University School of Medicine.
 
To learn more about PI Zeruesenay Desta, PhD and his research interests, please visit this link: https://medicine.iu.edu/faculty/4934/desta-zeruesenay

Eligibility of study

You may be eligible for this study if you meet the following criteria:

  • Conditions: Healthy
  • Age: 18 years - 65 years
  • Gender: All

Inclusion Criteria:
  • Overall general good health
  • Healthy body weight (BMI less than or equal to 32)
  • Able to refrain from taking medications or supplements that may interfere with the 3 FDA-approved study medications
Exclusion Criteria:
  • Have any significant health condition
  • Currently pregnant
  • Unwilling to refrain from alcoholic drinks during study period
  • Unwilling to refrain from drugs of abuse (including tobacco and/or marijuana) during the study
  • Unable to refrain from taking medications or supplements that may interfere with the 3 FDA-approved study medications

Updated on 04 Jun 2026. Study ID: CPHR-IIR-17726, 17726
Please visit our main page to search for other studies you may be interested in. If you need help finding a study or have any questions, please contact us at inhealth@iu.edu

Interested in the study?

This study is accepting only persons who receive care at a certain clinic or doctor or who are part of an invited group. Questions about this study can be directed to the study team listed in the description or contact your doctor to see if you are eligible.

Accepting Referrals by Invitation Only