Metabolite Ratios Rose During Repeated Oral THC While Parent THC Did Not Accumulate Similarly
During repeated dosing, 11-hydroxy-THC and THC-COOH increased over time without the same accumulation pattern for parent THC. A stable parent profile did not mean all measured cannabinoid exposure remained stable.
The analytes followed different courses
The six-person plasma study compared repeated oral dosing with measurements associated with cannabis use before admission. By day seven, metabolite-to-THC ratios were significantly higher than after the earlier self-administered cannabis exposure. The authors described continuing metabolite accumulation alongside relatively constant parent THC.
A ratio does not isolate one mechanism
A metabolite-to-parent ratio can change because of either component. The authors discussed possible metabolic explanations, but the observations did not directly establish a single enzyme mechanism. Route history, repeated dosing, timing and elimination all belong in the interpretation. A higher ratio should not automatically be converted into a larger known absorbed dose.
Keep the analytical form attached
The study measured free analytes and also evaluated hydrolyzed measurements with important recovery limitations. These definitions should not be silently combined into a complete total inventory. The observed profiles are pharmacokinetic findings in established users, not a threshold for impairment or evidence that metabolite concentration alone determines behavioral effects.
Related analysis: the repeated oral-THC plasma profiles.
Research cited
Schwilke and colleagues (2009). THC, 11-Hydroxy-THC, and THC-COOH Plasma Pharmacokinetics during and after Continuous High-Dose Oral THC. DOI: 10.1373/clinchem.2008.122119.
