Kavalactones are a class of lactone compounds found in the kava shrub. Kavalactones have a wide variety of effects including amnestic, analgesic, anticonvulsant, anxiolytic, nootropic, and sedative/hypnotic activity caused by numerous interactions with the central nervous system via a myriad mechanisms.
Kava extract has been shown to potently inhibit a wide range of hepatic enzymes, suggesting a very high potential for interactions with many pharmaceuticals and herbal medications. For this reason, kava should never be consumed without the permission of a primary care physician, psychiatrist, and/or any other doctor who is prescribing medication for a patient. It is also recommended that potential users discuss their kava use with a pharmacist.
Role in surgical complications
If undergoing anesthesia, it is recommended to note any use of kava well in advance of any surgery. Patients may be instructed to temporarily discontinue use of kava for a set period of time before and after the surgery to allow time for the longer-acting kavalacatones to clear the patients bloodstream. Due to its mild anti-coagulant property, wide range of pharmacological targets, and complex CYP450 hepatic enzyme inhibition and induction profile, there are numerous (physical, pharmaceutical, and pharmacokinetic) mechanisms through which recent kava consumption may induce and/or contribute to complications during both minor and major procedures. Since most kava preparations are not standardized and the ratio of kavalactone constituents varies with age and cultivar, the potential complications that may arise from failure to discontinue or reduce kava use as instructed by ones surgeon/doctor/anesthesiologist are not predictable and a lack of complications related to kava use shortly before or after a procedure is not a guarantee that complications will not emerge upon re-challenge of the same conditions.
Several kavalactones (e.g.Methysticin and Yangonin) have been reported to induce activity of CYP1A1. Hepatoxicity has been reported in a small portion of previously healthy kava users, particularly of extracts as opposed to whole root powders.
At least 18 different kavalactones have been identified to date, with methysticin being the first identified. Multiple analogues, such as ethysticin, have also been isolated. Some consist of a substituted α-pyrone as the lactone while others are partially saturated.
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