Iknow this is an old thread but coming of oxy 120mg+ isn't that roughly the equivalent of 75-85mg of methadone? I know half life plays a part in the duration but still, it would be crazy to jump off that without a taper or a shitload of other non opiate drugs.
I came off a 3 and a half 90mg oxy habit and had my last oxy dose 150mg and waited 24 hours and had 6mg of bupe then again 24 hours later. my eyes were pinned but i felt shit mentally and in mild WD, could still eat though. day 3 i used a combination of tramadol600mg, diazepam50mg. naproxen1100mg and promethazine75mg a day. I hadn't gone to the toilet since taking the first dose of bupe and took a strategic dose of rikodiene(Dihydrocodeine380mg) which is an OTC cough syrup and has sorbitol 88grams! in it which will make you piss shit. but i was backed up heaps and the sorbitol was a relief and counted the constipation completely.
6th day i felt like i was having a light WD from the subs even still didn't feel right with trams and valium. overall it wasn't until about 9 days until i felt nearly normal, but that day i got my refill and then life became normal again. I thought i planned for it well, but it was bad and i'd rate it close to one of my worst WD's
Buprenorphine did almost nothing for my WD I was still bedridden and found it hard to even sit on my comp. Imagine what it would have been like without anything? Fuck i would have been in a state for sure. cold turkey is crazy with anyone on any strong opiate for 3 months or more. unless you're dosing low(20mg oxycontin a day or 15mg of methadone) you never want to cold turkey it. you're more likely to relapse