mummymeister No, a GP wouldn't prescribe something like pregabalin for the purposes of weaning off another drug. It's not licensed for that. It's licensed for anxiety and neuropathic pain. Plus the DH isn't actually taking prescribed opiates, so to get prescribed pregabalin he'd have to tell the GP about his addiction, and the doctor would be even less likely to prescribe an addictive drug to a known addict. Their advice would be to wean himself off them with a taper at home.
The use of stuff like pregabalin, benzos etc for opiate withdrawal is generally something someone tries to obtain and carry out themselves as they don't want to mark themselves as an addict to professionals for fear of safeguarding issues, and future difficulty obtaining medication. Plenty of people do successfully carry out a home detox without any input from medics, if they can obtain the right drugs (illegally like her DH is doing). People who are always in fear of an opiate withdrawal round the corner will do absolutely anything to try and make it even a little more bearable so obtaining illicit drugs illegally is small fry to them.
But the fact remains pregabalin is habit forming and can be abused for a high alone. So I'm more inclined to think it's just another drug to add to his arsenal or possible backup for the times he can't get codeine, rather than an attempt at actually coming off codeine. Even if he managed that, staying off it is extremely difficult.
Once you've been dependent on opiates you've rewired your brain to see the euphoria from them as the best possible feeling you can ever have, an instant way of reducing all emotional pain, forgetting your problems, it's a warm safe blanket that makes you feel amazing, eases loneliness, takes away anxiety and makes you feel like you can conquer the world. You have a way of guaranteeing that each day you will feel not only happy but euphoric, instead of the pre opiate days where you have good and bad days and have to do difficult stuff like exercise and making effort with friends and eating right to maintain a good mood. Anything you used to do to feel happy that took effort can now be bypassed. People will rob, cheat, assault, to get that feeling back.
But quickly you end up where you're dependent and barely feel a high anymore, but if you don't take it you feel absolutely terrible, a feeling you can't even possibly begin to imagine unless you've experienced it, it's beyond imagination. So you take more and more to try get a ghost of that high you used to rely on, all the while increasing the amount you need daily to just feel normal.
That's probably where OP's husband is now. On an endless hamster wheel of putting so much effort in daily to source the codeine, knowing if he doesn't manage it he'll be in hell withdrawing. I'd be amazed if he hasn't started to mix it up with other opiates like heroin, tramadol, morphine. OP seems determined to stay aboard the sinking ship with him and their kids. It's sad. Nobody can save him but himself.