Worth mentioning here perhaps re: changa or ayahuasca - dangerous interactions between MAOI's or RIMAs and general anesthesia.
There is unfortunately not a plethora of studies on this, but here is a peer reviewed journal article on this topic for those interested:
The management of patients on psychoactive medications in the perioperative period is largely based on the individual clinician's experience. Despite ∼10%
ceaccp.oxfordjournals.org
RIMA's are perhaps less of a concern than orally ingested MAOI's, but I personally wouldn't risk either. I'll follow this with an excerpt of this article - the translation basically suggesting that the combination could precipitate a hypertensive crisis - particularly if the anesthetist or anesthesiologist is unaware that MAOI's are present in the system and the use of pressor agents to manage blood pressure could be catastrophic.
An excerpt:
The most important anaesthetic consideration for patients taking MAOIs relate to the profound pressor effect that may be seen after administration of both indirectly and directly acting sympathomimetics. The metabolism of indirectly acting sympathomimetics is inhibited, resulting in the potentiation of their action. Where absolutely necessary, direct sympathomimetics are preferable (by virtue of the fact that they are also metabolized by catechol-O-methyl-transferase so are not as dependent on MAO), but still require caution because there remains the risk of hypertensive crisis.
Meperidine can precipitate a serotonergic crisis in patients taking MAOI as it too interrupts presynaptic uptake of serotonin. It should therefore be avoided in patients known to be on an MAOI.
In the elective setting, there is some debate regarding the management of patients on MAOI. Although the risks associated with anaesthesia in those taking this group of drugs are significant, abrupt withdrawal may precipitate serious psychiatric relapse. Traditionally, irreversible MAOIs have been stopped 2 weeks before operation; however, omitting the dose of moclobemide on the day of surgery is acceptable. It has been suggested that in the elective situation, patients could be switched from an irreversible MAOI to moclobemide to avoid a prolonged period of discontinuation.2
When there is no time to consider withdrawal of MAOI, the anaesthetist must avoid meperidine and use only direct-acting sympathomimetics with extreme caution.
