Try a medical detox at a local hospital or at a drug treatment facility. The opiate-containing prescription
Tylenol is a narcotic and if he is abusing it, he should be treated as such. Lots of people take these pain killers for emotional pain. Narcotics actually cause physical pain, in the legs, for instance, which can only be relieved by taking more. It creates the symptoms it treats, or at least that is common. And concentrating on physical pain is often a great relief from emotional pain, which is why so many kids cut on themselves these days. He should also go to Narcotics Anonymous for personal support from people who've been there and to learn other ways of coping. NA is mostly full of kids, but there are also oldtimers who have a lot of experience to offer.
You might also consider going to a different type of meeting called NarcAnon yourself to make sure you don't get enmeshed in his problems and see what you can and can't do when you try to help him. You can find schedules and addresses for both meetings at
www.na.org.
As a recovering addict, I really wish you the very best. Just remember that it's his problem and his responsibility, not yours. Draw firm boundaries so his illness doesn't get you sick, too.