A single dose of kratom, a plant from Southeast Asia, produced some opioid-like effects in recreational polydrug users with opioid experience. In a double-blind, placebo-controlled study with 40 participants, kratom at doses of 3 grams or more caused pupil constriction, and the 12 gram dose increased ratings of drug liking, good effects, and high. No deaths or serious adverse events occurred; the most common side effects were somnolence, vomiting, and nausea. The findings suggest kratom can produce effects associated with drugs of abuse, but results may not apply to other kratom products.
Delta-8-THC, a cannabinoid growing in popularity for its reported therapeutic effects, was studied in male rats to understand its pharmacokinetics. After a single oral dose of 7.5 mg/kg, the compound showed very low oral bioavailability of 3.0%, with a peak plasma concentration of 13.4 ng/mL reached in 0.5 hours. Intravenous dosing at 1.25 mg/kg revealed a clearance rate higher than rat liver blood flow, suggesting elimination occurs partly outside the liver, and a large volume of distribution, indicating extensive movement into tissues. The elimination half-life was 13.9 hours. These findings suggest that oral Delta-8-THC is poorly absorbed, while its distribution and clearance patterns resemble those of other cannabinoids.