| Tylenol is terrible for your liver. Considering the half life of alcohol and tylenol, you should never take tylenol within five days of drinking. If you are taking orals, which are likely much rougher than alcohol, avoid tylenol completely. Here is some info copy and pasted from a Cecil Adams article:
Acetaminophen overdose is the leading cause of acute liver failure, even if we leave alcohol out of the picture. According to one study, it accounts for 20 percent of cases (Schiodt et al, Liver Transplantation and Surgery, January 1999) An as-yet-unpublished follow-up puts the number even higher--30 percent. Acute liver failure isn't that common. Still, 70,000 cases of acetaminophen toxicity are reported each year.
(Substitute methylated oral users for heavy drinkers)
...heavy drinkers (two or more drinks per day)... suffer worse liver damage from Tylenol than people who OD on purpose. Of 71 patients treated at a Dallas medical center for acetaminophen overdose, 50 were attempted suicides and 21 were victims of an accidental overdose (Schiodt et al, New England Journal of Medicine, October 1997). The would-be suicides on average took twice as much of the drug as the accidental victims. Yet far more of the latter went into a coma (seven versus three) and died (four versus one). Why? Because most of the accidental victims were alcoholics. Five people--three accidental victims, two attempted suicides--overdosed on less than four grams, the claimed safe dosage for 24 hours.
Let's not forget kidney damage. A December 1994 study in the New England Journal of Medicine found that a daily tablet of acetaminophen for a year or 1,000 pills over a lifetime doubled the odds of kidney failure. | 
