Ayahuasca and Methadone
Hello and thank you for reading, We are asked about Methadone and Ayahuasca frequently so please understand that what follows is my humble observation from experience and opinion and in no way medical advice.
There isnt a huge interaction between methadone and plant based maoi's (Monoamine oxidase inhibitor). It exists, but a known pharmacology professor i asked about this once said that he wasn't aware of any cases of bad reactions between the two. The reversible plant based maoi's you take with ayahuasca won't inhibit MAO strongly enough to allow anyone to have a serotonergic episode anyway. And their short duration means any potential problem would be over before it could cause much harm anyway. There is very little to zero risk with this combination, in my opinion.. however, it pays to be careful, as always. The contraindication of opiates and maois was a blanket statement put in the literature by the drug companies to cover their butts after one or two spectacularly bad cases involving demerol. However.. what they dont tell you is that a lot of people got demerol on maois without incident. There have been no cases (at least as of the time i researched it a few months ago) of negative interaction of regular opiates (morphine type) with maois, aside from the possibility for increased sedation, which is known. Do some research out there. there is a lot of information on MAOI interactions on anesthesiology webpages and psychiatry webpages. what i have discovered (being a long time maoi user for recreation and utility value) is that some of the interactions are overblown (maoi+opiate and maoi+dissociative), some of the interactions are more dangerous (maoi+sudafed, maoi+ssri). some, such as the combining of maois with dopaminergics and other antidepressants, are something that is left to individual case, and must be monitored carefully.
As to oxycodone (and codeine), a recent review article (Gillman 2005) suggests that it does not provoke serotonin toxicity with MAOIs because it lacks serotonin reuptake inhibitory property (at the difference of DXM and methadone for instance). Yet, if one wants to err on the side of total extra absolute safety, simple maths based on the longest known terminal half-life of oxycodone (w/ slow release tablets) give a delay of 18 hours to wait before drinking the tea. Reference Gillman, P.K. (2005). "Monoamine oxidase inhibitors, opioid analgesics and serotonin toxicity". British Journal of Anaesthesia, 95/4: 434-441