Mike I dont see why you cant but also dont see why you would as they basically have the same actions as one another and also an opiate with addictive properties.
With saying that they both have to be weaned off or you will have w/ds from either.
All you need to do on the methadone is a very slow taper and I know slow isnt what you wanted to hear and I do mean slow if you wish not to suffer any w/d.
The same with SubX,you have to go a slow taper.
Not knowing what dose your currently on I cant say for sure what would be a starting and stopping point but rule of thumb with methadone is to drop 5 MGS a week for 2 weeks and then continue that til your down to only 5mgs a day and then go to everyother day and then every 3rd and then you should be able to come off with anything more then the pain left. Like I said it is slow going and you have to have the mindset and be ready for going off.
Will you still miss the drug? of course but with this slow of a taper it will be what is left of the psychological thinking you need it noit so much the misery of the missing it physically.
I wish you alot of luck and if this is what your going to do then set your sights on the future and what your goal is dont let anything get in your way.
Bilateral knee replacements,spondylosis of L-3,4,5 and S-1, osteoarthritis,premenopausal migraines.
Meds: Methadone,xanax,zanaflex,maxide,prempro,K+,indocin,lexapro,neurontin(coming off) lyrica(going onto)