For how long does hydrocodone/acetaminophen last?

Last??: For pain, the useful period is generally 3-4 hours. If you mean how long does it stay in the body, it is rapidly metabolized and is only in the bloodstream in that form for a couple hours, is metabolized to Codeine and morphine, and those metabolites can last a day or two and be detected in urine, but they are not producing much activity, same with the tylenol (acetaminophen) in it.