Ugggggg, yeah this stuff happens. That said, 4 mg should actually be fine for him so long as he is getting good absorption when he takes them. The thing is, going directly from 8 to 4 could be a causing some minor withdraws. Most people stabilize after three or four days. The peak threshold for most people actually is around 4 mg. It might not hold him well for 24-hours though and if that is the case, split dosing around 12 hours apart usually helps with this - taking 2 mg in the morning and 2 at night.
Bup is actually much, much, stronger than was first thought and most patients believe. I hear these stories of people on 24 or even 32 mg a day and it's just being wasted. It's doing nothing other than they THINK it is. Truth is they would feel exactly the same on 8 mg. When tapering lower, people typically really start to feel the difference when getting to 3 and for certain 2 mg. From there, going very slowly with small drops is the way to taper off. We recommend going all the way down to 0.25 mg if not 0.125 and then stopping.
While I would rather see his friend getting treated from a physician, you may want to tell him he will still feel pretty crappy if he tries to stop at 4 mg. He really should get himself down to 1 mg at least with a quick taper. The problem is, withdraws are only the start of recovery. So many think if they can just get clean and clear of the drugs and out of withdraws their nightmare will be over. Sadly they quickly find themselves right back where they started. This is again why addicts should be on medication for at least a year or until their brains are fully developed (about age 27), and they have done all of the other work necessary to recovery. Quick detoxes just don't often work.
Very glad to hear your son is still on Bup. and still doing relatively well.
DonH Midwest Me 56 WAW-EXW 55 Met 11/95 / Married 5/00 Bomb 6/20/05 / She Filed on 6/2/06 / Divorced on 10/9/06 4 who'd qualify as GF since D & dated about 25 women since D