Twenty-two of 25 compounds in kratom bind to mu-opioid receptors.
In newly-released scientific analysis and data, the FDA has indicated strong evidence of the presence of compounds in kratom that strongly bind to opioid receptors, according to a statement released by FDA Commissioner Scott Gottlieb, MD.
The new data contributes to the agency’s concern about kratom’s potential for abuse. In November 2017, the FDA issued a public health advisory on the product to warn consumers about potential risks associated with its use.
To analyze the chemical structure of kratom’s compounds, the FDA used a computational model called the Public Health Assessment via Structural Evaluation (PHASE) methodology. According to the statement, PHASE uses the molecular structure of a substance to predict its biological function in the body. From this analysis, FDA researchers concluded that all of the compounds share the most structural similarities with controlled opioid analgesics, such as morphine derivatives.
Additionally, the researchers found that 22 of the 25 compounds in kratom bind to mu-opioid receptors, and that some of the compounds may bind to receptors in the brain that may contribute to stress responses that impact neurologic and cardiovascular function.
In the advisory released in November, Dr. Gottlieb referenced 36 reported deaths linked to use of kratom-containing products, and cited instances of kratom laced with other opioids like hydrocodone. He noted that, “Given all these considerations, we must ask ourselves whether the use of kratom—for recreation, pain, or other reasons–could expand the opioid epidemic.” However, he stated that the agency recognizes that there is still much that is unknown about kratom.
The statement released today detailed the reports on kratom-associated deaths. Dr. Gottlieb noted that most instances could not be fully assessed due to limited information, although the fatalities raised concerns about kratom being used in combination with other drugs that affect the brain.
Dr. Gottlieb concluded that there is no evidence to support kratom’s safety or efficacy in any medical use. “Further, as the scientific data and adverse event reports clearly revealed, compounds in kratom make it so it isn’t just a plant—it’s an opioid,” Dr. Gottlieb said in the statement.
Statement from FDA Commissioner Scott Gottlieb, M.D., on the agency’s scientific evidence on the presence of opioid compounds in kratom, underscoring its potential for abuse [FDA statement]. FDA’s website. https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm595622.htm. Accessed February 7, 2018.