How Long Does Tylenol #3 Stay in Your System?

The Half-Lives of Acetaminophen and Codeine

Man taking prescription pills out of medicine cabinet
Tylenol #3 Can Interact With Other Drugs.

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Tylenol #3, also known as Tylenol with codeine, is a prescription version of the same medication that's available over the counter at the drugstore. You've probably reached for Tylenol (or its generic version, acetaminophen) more than once to treat a headache, say, or to ease muscle soreness after a tough workout. Some people also take acetaminophen to bring down a fever.

The addition of codeine, an analgesic (pain reliever) that works on the central nervous system, is the reason Tyelonol #3 is available only by prescription. Codeine is an opiate, or narcotic, and as such can be habit-forming if not taken exactly as directed by a doctor.

Codeine also can be extremely dangerous if there's too much of the drug in the body at once, whether it's taken alone or as an active ingredient in Tylenol #3. The same may be true of acetaminophen even though it's a non-narcotic pain reliever, but for different reasons.

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. Both acetaminophen and codeine have risks for serious interactions with other medications and overdoses. If you know more about how long Tylenol #3 stays in your body, you may better understand how to avoid these reactions.

The Half-Lives of Acetaminophen and Codeine

In order to predict how long any medication might remain active in the body, it's important to understand how quickly it's metabolized. This is expressed as its "half-life." This term refers to the amount of time it takes for half of a dose taken to be eliminated from the bloodstream. Put another way, the half-life of a medication is the time it takes for the drug to naturally dilute to half of its original concentration.

The half-lives of the components of Tylenol #3 are slightly different:

  • Acetaminophen. Each Tylenol #3 tablet contains 300 milligrams (mg) of acetaminophen. For most people, this amount of Tylenol has a half-life in the blood of 1.25 to 3 hours. All of the drug will have passed out through the urine within 24 hours. Note that this could take longer in someone who has poor liver function.
  • Codeine. There is 30 mg of codeine in a single Tylenol #3 tablet. Codeine takes longer to clear from the system than acetaminophen does. Typically it has a half-life of 2.5 to 3 hours and it can continue to work in the body for 4 to 6 hours. Codeine continues to show up in urine for as many as three days after being taken. If for some reason you have to have a urine screen in that time there's a good chance the results will be positive for opiates.

Because of the codeine, therefore, when regarded as a single medication, Tylenol #3 stays in the system for up to three days.

Risks of Tylenol #3

Acetaminophen has a narrow safety range. If you take more than 4,000 mg per day, you risk irreversible liver damage that ultimately can lead to death. This can happen more easily than you might think because acetaminophen is an ingredient in many different medications, such as cold or allergy drugs designed to target multiple symptoms.

For this reason, combination medications like Tylenol #3 are limited to no more than 325 mg of acetaminophen per tablet, capsule, or other dosage unit but you should take responsibility for your safety as well if you're taking Tylenol #3.

Before you take anything else, read the ingredients list carefully. If the medication contains acetaminophen (or, in Europe, paracetamol), note how many milligrams there are per dose and do the math to make sure you don't exceed 4,000 mg in a 24-hour period. Safer yet, talk to your doctor or pharmacist.

Having too much codeine in the body poses several risks. For one thing, the drug can be habit-forming, meaning it could cause a person to become addicted to it. Codeine also may cause serious breathing problems, especially during the first day or two of taking it. In fact, it's generally recommended that people who have conditions such as asthma or chronic obstructive pulmonary disease (COPD) not take codeine.

Codeine can interact with other medications and substances, too. Because it affects the central nervous system, you should be careful not to take other drugs that can slow breathing or cause drowsiness while taking Tylenol #3 or before it's likely to have clear from your system.

Also, while taking Tylenol #3 you shouldn't take medications containing acetaminophen, antidepressants, cold or allergy medicines, pain relievers, sedatives, sleeping pills, and tranquilizers. You shouldn't drink alcohol either. Tell your doctor about all prescription, non-prescription, and over-the-counter medications you're already taking if he prescribes Tylenol #3 for you.

Signs of a Tylenol #3 Overdose

These symptoms of a potential overdose should prompt you or anyone who's caring for you to get emergency help right away.

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