Could SSRI’S (eg. Effexor) Metabolise Methadone faster??

Methadone treatments have been the gold standard for treating opioid addictions for decades. What are the advantages of methadone? Questions about methadone-assisted treatment go here.
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Could SSRI’S (eg. Effexor) Metabolise Methadone faster??

Post by Doves7171 »

I’m currently on 12mg Suboxone film once per day. I’ve been on since 2014 but with a 12 month stint on Methadone from 2017. Hellish going from M to Subs but that’s another story.

When I did the 12 months on methadone from 2017 to 2018 at 90mg once per day, I noticed at the approximately 20 hour mark I was going into a nasty space, IE. that last 3 or 4 hours anticipating my next methadone dose, I was depressed, low on life, stricken with worry and fear, I wouldn’t say I was sweating, or having many physical symptoms of withdrawal, more so mental and low on life, although walking outside was a struggle like a block was like walking 10 blocks.

From a couple of other posters here on the forum, I rationalise that the SSRI I was on Effexor (venlefaxine) could’ve been the culprit to this rapid metabolism of my methadone dose. When I took my methadone it brought me up beautifully, gave me vigour, focus and a happy outlook on life. It was just those last few hours that felt hellish.

Now from studies conducted, St Johns Wort has been implicated as a rapid metaboliser of Methadone, so I’m wondering anyone’s experiences on Effexor added to Methadone.

I was considering switching back to M but I’m still on Effexor and I fear it may put me in the same space as a few years ago.
Any thoughts?
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Re: Could SSRI’S (eg. Effexor) Metabolise Methadone faster??

Post by suboxdoc »

Man, I hate Effexor.... Too many side effects but they must do great marketing because so many people take it!!

Methadone is broken down (at least initially) by an enzyme called cytochrome CYP3A4. If you Google CYP3A4 and go to the wikipedia site, you'll see a list of 'substrates', 'inducers' and 'inhibitors'. Substrates are medications like Effexor and methadone that are metabolized by that enzyme. The amount of that enzyme is increased by substances called 'inducers' and decreased by 'inhibitors'. Venlafaxine is not known to do either -- but who knows. Maybe there are individual differences? It would be interesting to have you on a constant dose of methadone, and then check your peak and trough blood levels with you on and then off Effexor. Of course you can see how difficult that would be, taking months to get on or off the various meds....
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