Hi ...I used to take Methadone 5mg 3x daily but could not cope with being sedated and having problems srtinging sentences together. It was far better to have increased pain and be off it tho' it made me quite ill from withdrawal effects. I even reduced the dose but ended up quite ill with hideous body pain for about 6 weeks. I was basically in bed for two weeks. I stayed on and continue to take 100mg oral Ketamine 2x, 600mg Lyrica tho' was up to 900mg a wee while ago but have got it back down. I take Venlafaxine 75mg in morning and 27,5mg at night. Have to take anti emetic and gastro protection. As an add in to help me go out or do something I take Meptazinol 200mg up to 3x daily and then switch out with Nefopam to reduce tolerance effects...
I have a lot of drugs and manipulate them according to cut of dose given. My docs are great. Tried cutting Ketamine down but get more pain.
It is trial and error and a good doc. Also have Migraines to boot.

Don't think there is an effective combination that can be prescribed as we are all different.
Best wishes and find some relief soon.
Hx