Tramadol LD50 (Source: Wikipedia)
228 mg·kg (LD50, Ratte, oral)
350 mg·kg (LD50, Maus, oral)
200 mg·kg (LD50, Maus, s.c.)
They are all not made to really OD on. I rely on the info I can find using search engines. If that method had a high success rate it'd be more discussed here in my opinion it has a high failure risk even with alc.