Vyvanse (lisdexamfetamine) interaction questions

[~Odysseus~]

I'm currently prescribed 30mg Vyvanse daily for ADHD. For those who don't know, Vyvanse contains lisdexamfetamine which slowly breaks down into dextroamphetamine in the bloodstream.

5 days ago I did some LSD, but on a day I didn't take my medication and all went well. I was curious how psychedelics may interact with my medication if I was still under the influence of it.

My primary concern comes with MAOIs, since I plan to use more ayahuasca brews sometime in the future. I wasn't sure if just waiting a day or so was enough to begin taking MAOIs, since I know the combination can be dangerous with amphetamines. The FDA has a period of 14 days between last dose of Vyvanse and an MAOI. Such a wait would be really inconvenient for me. It's not like I need my meds to survive, but they help tremendously and I was curious if I could get a second source of information and/or experience.

 

[blig-blug]

Amphetamines don't interact with most psychedelics in pharmacological dangerous ways, although they obviously can qualitatively affect the experience. In most cases, I would do what you did: not take the medication for that day, but without waiting for longer.

My primary concern comes with MAOIs, since I plan to use more ayahuasca brews sometime in the future. I wasn't sure if just waiting a day or so was enough to begin taking MAOIs, since I know the combination can be dangerous with amphetamines. The FDA has a period of 14 days between last dose of Vyvanse and an MAOI. Such a wait would be really inconvenient for me. It's not like I need my meds to survive, but they help tremendously and I was curious if I could get a second source of information and/or experience.

Yes, your concerns about that are correct: [Harmalas] MAOI Drug Interaction Disclaimer

Lisdexamfetamine is converted into dextroamphetamine quite fast (it will have almost fully converted in less than 6 hours), so you can consider it dextroamphetamine for half-life purposes. Dextroamphetamine has a half-life of around 10 hours, and it's a good rule of thumb to wait for around 6 half lives, so 60 hours or 2.5 days. I'd wait for three days to be on the safe side (and have done so in the past, although the dose of amphetamine I occasionally take is only 5mg).

This is a minimum, the more you wait, the safer. The FDA guidelines are that long likely out of caution. Also, they will have taken into consideration non-reversible MAOIs, which are more potentially dangerous than reversible ones like harmalas (that doesn't mean harmalas aren't dangerous in combination with amphetamines, do wait for enough time!).

 

[~Odysseus~]

Thanks for this information! I never really heard of there being reversible and non-reversible MAOIs until now. It seems it takes about 2 weeks for the body to produce those enzymes again from non-reversible MAOIs which lines up with the FDA guideline. It's kind of relieving to know I won't have to go unmedicated for 2 weeks just so I can consume ayahuasca or Changa, which the latter I've never even experimented with yet.

 

[weirdoigo]

what about the safe time to resume the dex after harmalas? is there a window?

 

[Voidmatrix]

Thanks for this information! I never really heard of there being reversible and non-reversible MAOIs until now. It seems it takes about 2 weeks for the body to produce those enzymes again from non-reversible MAOIs which lines up with the FDA guideline. It's kind of relieving to know I won't have to go unmedicated for 2 weeks just so I can consume ayahuasca or Changa, which the latter I've never even experimented with yet.

Irreversible MAO Inhibitors: These compounds, which include well-known drugs like phenelzineand tranylcypromine, form a covalent bond with the flavin adenine dinucleotide (FAD) cofactorof the MAO enzyme.[3][6] This binding is essentially permanent, rendering the enzyme inactive.[3][7] Restoration of MAO activity is not possible until new enzyme is synthesized by the body,a process that can take up to two weeks.[3] This prolonged and cumulative inhibition, reachingup to 90% or more, is a key feature of their potent therapeutic effect.[8]Reversible MAO Inhibitors (RIMAs): In contrast, reversible inhibitors, such as moclobemide, donot form a covalent bond.[6][7] They bind to the active site of the MAO enzyme through weaker,non-covalent interactions. This binding is competitive and concentration-dependent, meaningthe inhibitor can be displaced from the enzyme, allowing for the restoration of enzyme activityas the drug is metabolized and cleared from the body.[7][9]

Reversible inhibitors of MAO-A (RIMAs) have a much lower risk of this interaction.[9] In thepresence of high tyramine concentrations, the reversible inhibitor can be displaced from theMAO-A enzyme, allowing for the metabolism of tyramine and mitigating the hypertensiveresponse.[9]

A Comparative Analysis of Reversible and Irreversible Monoamine Oxidase Inhibitors: Mechanisms, Applications, and Safety Profiles

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