But I do still have a lingering question: What about precipitated WDs? Aren't those based on the fact that adminstering suboxone or buprenorphine to someone high on heroin causes the bupe to kick off the heroin from the mu receptors and replace it with bupe? And because the dose of bupe given USUALLY is less potent than the dose of heroin sitting on the receptors, the person goes into precipitated WDs. Using that logic, if someone is ODing on heroin, wouldn't adminstering a moderate does of buperenorphine with or without naloxone cause the heroin to be kicked off the receptors to be replaced by the bupe, and thus causing the person to go into precipitated WDs just like a normal person is just high instead of ODing?
Sorry for all these questions, but I've always wondered this and its kind of fascinating to me since I am curious about pharmacology. Thanks for any info.
Precipitated withdrawal works like this, in this situation. You are a Heroin addict. You use Heroin two or three times a day. You used Heroin this morning, and then maybe 6 hours later, you get a sniffle and think you're getting sick, so you put a Subutex/Suboxone under your tongue. When the Buprenorphine is absorbed and gets into the bloodstream, it displaces the Heroin that was attached to the mu receptors- meaning, the Buprenorphine has a higher affinity (it has stronger means for bonding
). But, Buprenorphine, despite having higher affinity for these receptors, is a partial agonist.
Heroin is a
stronger agonist than Buprenorphine, but has a weaker affinity than Buprenorphine does. Think of it like watching porn. Who do you think should be in a porn movie; the guy with the really big muscles and small penis, or the guy whose really scrawny with a big penis? Works like that.
So, the mu receptors are at one moment being agonized heavily (deeply and repeatedly) by Heroin, all of a sudden Buprenorphine scares him off with his bigger affinity, but the receptors aren't getting agonized as deeply as they were a moment ago.
Precipitated withdrawal is the result of this competition and change; after awhile the body regains stasis and the precipitated withdrawals go away (the Heroin will remain in your system even though it has been outcompeted for the mu receptors; but it won't re-bind because Buprenorphine will last longer than the Heroin left in your body). Also, while in PW, the Buprenorphine is bound to those mu receptors. Even though you are in withdrawal, the Buprenorphine is still in your system doing its job- meaning, you can't inject Heroin or another full agonist and expect relief: as the Bupe will simply continue to outcompete it/them.
Hope that helps.
Given the difference in bioavailablity (33% Sublingual to 100% I.V) - if you are injecting 2mg Subutex a day, do you have the same habit of someone who is putting around 6mg under their tounge?
Nope, onset and duration are very different.
Similar to the 'Is taking 300mg Codeine the same as taking 30mg Morphine?'
The answer is kinda but no, no it isn't.
