The half-life of codeine is around three to four hours, which means that an entire dose of codeine will leave your system in approximately 16 hours or less. The combination of acetaminophen and codeine may be habit forming, especially with prolonged use. Take acetaminophen and codeine exactly as directed. Do not take more of it, take it more often, or take it in a different way than directed by your doctor. While taking acetaminophen and codeine To prevent an overdose of either medication it can be helpful to understand how long they stay in the body so that you don't risk overlapping a new dose of either ingredient with medication that's still circulating in your system. Tylenol is associated with serious complications, including liver damage and rare but dangerous skin reactions. It is the leading cause of acute liver failure in the U.S., and the drug in some cases led to fatalities. How Long Do Opiates Stay in Your System? Learn about Blood, Urine, & Saliva testing, or How to Flush Your System of Opioids like Heroin, Hydrocodone, Oxycodone, Codeine, Fentanyl, Methadone, & Morphine. Get help and share your story with others who know what you're going through. first of all i did my research and at the time it was considered an opiod-like not an actual narcotic. Second how on god's green earth is my answer to be considered fatal. Percocet is a pain reliever that's prescribed for people with moderate to severe pain. It contains the narcotic oxycodone, an opiate analgesic medication, and acetaminophen (Tylenol), a non-narcotic pain reliever and fever reducer. Doctors give trusted answers on uses, effects, side-effects, and cautions: Dr. Rosenfeld on how long will hydrocodone stay in your system: Why are you asking this question? Be honest. I take tylenol 1's with 8mg of codine on a daily basis,how long will it be in my system if I were too stop now?.