Abrupt Opioid Withdrawal Increases Pain Sensitivity

[Justin]

Here's a link that explains the original Science publication below: LINK...it's a good read.

"Induction of synaptic long-term potentiation after opioid withdrawal"
Ruth Drdla, Matthias Gassner, Ewald Gingl and Jürgen Sandkühler.
Science 325 (2009).

[KBear]

Justin, I have heard, that being on opiods for a long period of time, makes you more sensitive to pain. I am not sure if there is any truth to that, have you heard anything of the sort? I think the explanation I got was that the opiod replaces endorphins, so your body quits making as many (or maybe any), thus causing more pain. Would love to know if there is any science behind that??

[Justin]

Justin, I have heard, that being on opiods for a long period of time, makes you more sensitive to pain. I am not sure if there is any truth to that, have you heard anything of the sort? I think the explanation I got was that the opiod replaces endorphins, so your body quits making as many (or maybe any), thus causing more pain. Would love to know if there is any science behind that??

The short of it is that it's true. The opioids that we naturally make are down-regulated when on chronic synthetic opioid therapy. Receptor-mediated signaling (mu, kappa, delta) is thus affected:

Long-term or high dose use of opioids may also lead to additional mechanisms of tolerance becoming involved. This includes downregulation of mu opioid receptor gene expression, so the number of receptors presented on the cell surface is actually reduced, as opposed to the more short-term desensitisation induced by β-arrestins or RGS proteins.[12][13][14] Another long-term adaptation to opioid use can be upregulation of glutamate and other pathways in the brain which can exert an opioid-opposing effect and so reduce the effects of opioid drugs by altering downstream pathways, regardless of mu opioid receptor activation.[15][16] LINK