Active metabolitesWhen a drug enters the body, two things happen. One is that the drug has an effect on the body, which is known as pharmacodynamics. The other thing that happens is that the body acts on the drug, known as pharmacokinetics. One of the body’s responses to compounds entering the body is to metabolize them into a form that can be more easily excreted from the body. Some of the compounds, called metabolites, are also pharmacologically active.
11-Hydroxy-Tetrahydrocannabinol (11-OH-THC)11-OH-THC is a metabolite of THC that is formed in the liver by several enzymes, mainly CYP2C9 and CYP3A4.1, 2 One study showed that 11-OH-THC should be more potent than THC in humans: when THC and 11-OH-THC were given at different times, the subjects rated the feeling ‘high’ measure from 11-OH-THC as more intense.3 One theory is that 11-OH-THC crosses the blood-brain barrier more easily than THC, allowing it to exert a stronger psychoactive effect.4 References:
- Dinis-Oliveira, Ricardo Jorge (2016). Metabolomics of Δ 9 -tetrahydrocannabinol: implications in toxicity. Drug Metabolism Reviews, 48(1), 80--87.
- Watanabe, Kazuhito; Yamaori, Satoshi; Funahashi, Tatsuya; Kimura, Toshiyuki; Yamamoto, Ikuo (2007). Cytochrome P450 enzymes involved in the metabolism of tetrahydrocannabinols and cannabinol by human hepatic microsomes. Life Sciences
- Lemberger, Louis; Martz, Robert; Rodda, Bruce; Forney, Robert; Rowe, Howard (1973). Comparative pharmacology of Delta9-tetrahydrocannabinol and its metabolite, 11-OH-Delta9-tetrahydrocannabinol. The Journal of clinical investigation (2411--7).
- Schou, J.; Prockop, L. D.; Dahlstrom, G.; Rohde, C. (1977). Penetration of delta-9-tetrahydrocannabinol and 11-OH-delta-9-tetrahydrocannabinol through the blood-brain barrier. Acta pharmacologica et toxicologica, 41(1), 33--38.