The respiratory depressant effects of mitragynine are limited by its conversion to7-OH mitragynine

Expanded 2-paragraph summary at a 6th grade reading level:

Mitragynine is a chemical found in the kratom plant. Kratom is used by some people to help with pain or as an alternative to other drugs. The researchers in this study wanted to understand how mitragynine affects breathing in mice. They found that mitragynine can depress breathing, but only up to a certain dose. At higher doses, the effects on breathing did not increase.

The researchers think this is because mitragynine gets changed into another chemical called 7-OH mitragynine inside the body. 7-OH mitragynine is better at affecting the opioid receptors in the body, which can depress breathing. But the conversion of mitragynine to 7-OH mitragynine has a limit, so the effects on breathing also have a limit. This may explain why kratom seems to have a safer profile than other opioid drugs.

This study was done in a lab, not in the real world. The researchers used mice, not humans, in their
experiments

Key takeaways:

  • Mitragynine can depress breathing in mice, but only up to a certain dose
  • This ceiling effect is due to mitragynine being converted to 7-OH mitragynine, which is more potent
  • The limited conversion of mitragynine to 7-OH mitragynine may explain why kratom appears to have a safer profile than other opioid drugs
  • This study was done in mice, not humans, in a lab setting

For further reading:

https://bpspubs.onlinelibrary.wiley.com/doi/10.1111/bph.15832

Full Citation:

Hill, R., Kruegel, A. C., Javitch, J. A., Lane, J. R., & Canals, M. (2022). The respiratory depressant effects of mitragynine are limited by its conversion to 7-OH mitragynine. British Journal of Pharmacology, 179(14), 3875-3885