Recruiting

Early Phase 1

Kratom with OxycodoneEvaluating a Potential Pharmacokinetic Kratom-oxycodone Interaction Concurrent With Clinical Endpoints

Sponsor:

Washington State University

Code:

NCT05846451

Conditions

Herbal Interaction

Eligibility Criteria

Sex: All

Age: 21 - 45

Healthy Volunteers: Accepted

Interventions

Kratom

Oxycodone

Study Details

Brief summary:

The goal of this study is to investigate whether the botanical product kratom affects how the body processes the opioid drug oxycodone. The main research questions to be answered are two-fold:

1. How does kratom affect the manner in which oxycodone is metabolized (broken down and removed) by the body?
2. Does kratom change the effects oxycodone exerts on the body?

Healthy adult participants will complete four study arms, during which they will be given the following:

Kratom (as a tea)
A single dose of oxycodone (as a tablet)
Kratom tea and a single dose of oxycodone
Kratom tea for four days, then kratom tea and a single dose of oxycodone

Conditions

Herbal Interaction

Study ID

NCT05846451

Start date

Jun 1, 2023

Status verified date

Jun, 2026

Completion date

Dec 1, 2026

Anticipated

Primary completion date

Nov 1, 2026

Anticipated

Eligibility Criteria

Sex: All

Age: 21 - 45

Healthy Volunteers: Accepted

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

Study Design

Enrollment

16 participants

Anticipated

Allocation

Non randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Arm 1

Sixteen non-naive\* participants (8 males, 8 females) will be administered a single low dose (2 g) of a well-characterized kratom product by mouth as a tea. Pupil diameter will be measured from 0-12 hours. A washout of at least 10 days will separate Arms 1 and 2.

\*Non-naive subjects are defined as intermittent users who consume 2-8 g kratom at least once per month but no more than three times daily within the last six months prior to screening and are willing to abstain for several weeks

active comparator: Arm 2

The same 16 participants will be administered a single low dose (10 mg) of immediate-release oxycodone by mouth as a tablet. Plasma, pupil diameter measurements, and urine will be collected from 0-24 hours. A washout of at least 2 days will separate Arms 2 and 3.

experimental: Arm 3

The same 16 participants will be administered a single low dose (2 g) of kratom as a tea. After 15 minutes, the subjects will be administered a single low dose (10 mg) of oxycodone as a tablet by mouth. Plasma, pupil diameter measurements, and urine will be collected from 0-24 hours. A washout of at least 10 days will separate Arms 3 and 4.

experimental: Arm 4

The same 16 participants will self-administer a single low dose (2 g) of kratom as a tea once daily at home. On the fifth day, subjects will return to the research setting, where they will be administered a single low dose (2 g) of kratom, followed 15 minutes later by a single low dose (10 mg) of oxycodone by mouth. Plasma, pupil diameter measurements, and urine will be collected from 0-24 hours.

Interventions

Kratom

Kratom (Moon Kratom Yellow Indonesian, lot 51) is supplied as a dry leaf powder in clear plastic bags, each weighing 5 kg. Two grams of kratom dry leaf powder will be stirred into 240 mL of hot water to make a tea. The tea will be cooled to 50 degrees Celsius before administration. Participants will drink the tea within 15 minutes.

Oxycodone

Immediate-release oral tablet, 10 mg

Primary outcome measure

Oxycodone area under the concentration vs. time curve (AUC) ratio (presence to absence of kratom) [ Time Frame: 0-24 hours ]

Central Contacts and Locations

Central contacts

Mary Paine, PhD

509-358-7759 mary.paine@wsu.edu

Deena Hadi, BS

509-368-6692 deena.hadi@wsu.edu

Locations

Washington State University College of Pharmacy and Pharmaceutical Sciences

Recruiting

Spokane, Washington, United States, 99202

Contacts

Mary Paine, PhD, RPh

mary.paine@wsu.edu

More Information

Sponsor

Washington State University

Last update posted

Jun 3, 2026

Last verified

Jun, 2026

Keywords

pharmacokinetic
pharmacokinetics
pharmacodynamic
pharmacodynamics
kratom
oxycodone
natural product
botanical product
natural product-drug interaction
mitragynine

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Washington State University on 2026-06-03.