Investigating how kratom affects oxycodone metabolism and effects

Evaluating a Potential Pharmacokinetic Kratom-oxycodone Interaction Concurrent With Clinical Endpoints

EARLY_PHASE1 · Washington State University · NCT05846451

This study is testing how kratom affects the way the body processes oxycodone and its effects on healthy adults.

Quick facts

PhaseEARLY_PHASE1
Study typeInterventional
Enrollment16 (estimated)
Ages21 Years to 45 Years
SexAll
SponsorWashington State University (other)
Locations1 site (Spokane, Washington)
Trial IDNCT05846451 on ClinicalTrials.gov

What this trial studies

This study aims to evaluate the interaction between kratom, a botanical product, and the opioid oxycodone. Healthy adult participants will undergo four different treatment arms, receiving either kratom, oxycodone, or both in various combinations. The primary focus is to assess how kratom influences the metabolism of oxycodone and its effects on the body, particularly through measuring pupil diameter as an indicator of opioid effects. Participants will be closely monitored to gather data on pharmacokinetics and pharmacodynamics.

Who should consider this trial

Good fit: Ideal candidates are healthy adults aged 21-45 who are not taking any medications or supplements that could interfere with the study.

Not a fit: Patients with existing health conditions or those taking medications that affect drug metabolism may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into safer use of oxycodone in patients who may also use kratom.

How similar studies have performed: While there is limited research on kratom's interaction with opioids, this study explores a novel area that has not been extensively tested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Males and females, aged from 21-45 years and healthy
* Body weight between 130 and 250 pounds (60-115 kg) and body mass index between 19 and 30
* Not taking any medications (prescription and non-prescription) or dietary supplements/botanical products known to alter the pharmacokinetics of either oxycodone or kratom
* Willing to abstain from consuming dietary supplements/botanical products and fruit juices for several weeks
* Willing to abstain from cannabis/marijuana, hemp, and THC- and/or CBD-containing products for several weeks
* Willing to abstain from consuming caffeinated beverages or other caffeine-containing products the evening before and morning of any inpatient visit
* Willing to abstain from consuming alcoholic beverages for one day prior to any inpatient visit
* Willing to use an additional method of contraception that does not include oral contraceptive pills, patches, or other hormonal methods (such as abstinence, copper IUD, or condoms)
* Have consumed kratom previously and tolerated it well without any unpleasant effects
* Willing to abstain from kratom for several weeks
* Have consumed any opioid previously and tolerated it well without any unpleasant effects or addiction
* Written informed consent (and assent when applicable) obtained from subject or subject's legal representative and ability for the subject to comply with the requirements of the study
* Geographically located within a 40-mile radius of Spokane and have the time to participate

Exclusion Criteria:

* Males and females under the age of 21 or over the age of 45
* People who weigh less than 130 pounds or more than 250 pounds
* People with a body mass index less than 19 or greater than 30
* Any current major illness or chronic illness including but not limited to kidney disease, hepatic disease, diabetes mellitus, hypertension, coronary artery disease, chronic obstructive pulmonary disease, cancer, or HIV/AIDS
* No previous exposure to kratom
* No previous exposure to an opioid
* History of anemia or any other significant hematologic disorder
* History of substance abuse, dependence, or addiction or major psychiatric illness
* A need for chronic opioid analgesics
* Use of opioid analgesics 3 weeks prior to initiation of the study
* An imminent likely need for opioid analgesics (e.g., planned dental or surgical procedure)
* Pregnant or nursing
* History of allergy or intolerance to kratom, other opioids, or oxycodone
* Taking concomitant medications, both prescription and non-prescription (including dietary supplements/botanical products), known to alter the pharmacokinetics of kratom or oxycodone
* Presence of a condition or abnormality that, in the opinion of the Investigator, would compromise the safety of the patient or the quality of the data
* History of sleep apnea
* Any prior use of amphetamines, benzodiazepines, cocaine, MDMA, opioids, PCP, or other drugs for recreational purposes
* Use of cannabis/marijuana, hemp, THC-containing products, CBD-containing products, or CBD within the last month
* Out-of-range clinical laboratory value that the study physician considers participation in the study a health risk
* Inability to speak, read, and understand English

Where this trial is running

Spokane, Washington

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Herbal Interaction, pharmacokinetic, pharmacokinetics, pharmacodynamic, pharmacodynamics, kratom, oxycodone, natural product

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.