Well I'm sure you know that they give chlordiazepoxide and/or lorazepam to smooth detox. Should be enough to at least reduce his anxiety to manageable levels and prevent seizure. All kinds of benzos with different alpha PAM (redundant, I know) affinities, really. It won't do much good for other withdrawal effects, as I was led to understand.
But there are a few things going for him. One, that he's using a legal drug (not to say that it's safer in a vacuum via comparison), and two that they have medications to deal with some of the withdrawal (reiteration). Thank goodness meth wasn't his DOC.
If the guy has some underlying issues otherwise, too, then those can be treated safely. Like depression, I'd guess.
I will say that, if he's yellow, things have gotten near the point of no return. Still, the liver is very regenerative.
Hope this helps.