How to take your medicine: acetaminophen-codeine

FDA Consumer, Jan-Feb, 1991 by Judy Folkenberg

How to Take Your Medicine

How you take a drug can be very important to both its effectiveness and safety. Sometimes it can be almost as important as what you take. Timing, what you eat and when you eat, proper dose, and many other factors can mean the difference between feeling better, staying the same, or even feeling worse. This drug information page is intended to help you make your treatment work as effectively as possible. It is important to note, however, that this is only a guideline. You should talk to your doctor about how and when to take any prescribed drugs.

This installment in a series of articles on commonly prescribed drugs is about acetaminophen-codeine combinations.

One of the most widely prescribed drugs and the most commonly prescribed pain reliever in the United States, acetaminophen-codeine is a combination of two medicines: acetaminopehn, a pain remedy commonly found in such drugs as over-the-counter Tylenol; and codeine, a narcotic (morphine-like drug) that acts as a painkiller.

More than 28.5 million prescriptions for acetaminophe-codeine combinations were filled in 1989 in American drugstores.

Conditions These Drugs Treat

The medication is prescribed for many different kinds of pain, ranging from migraine headaches and broken bones or sprains to dental or post-surgical pain. It is also sometimes prescribed to reduce coughing.

How to Take

Take this medicine only as directed by your physician or dentist. Do not take for a longer time than your doctor has prescribed. This drug is a narcotic and may be habit-forming. Even if the drug is not relieving the pain as well as you think it should, do not increase the dose without checking with your doctor or dentist.

Missed Doses

If you are taking this drug on a regular schedule and skip a dose, take it as soon as you remember. If it is nearly time for your next dose, skip the missed dose and get back on your regular dosing schedule. Do not double doses.

Relief of Symptoms

Relief of the pain usually begins 15 to 30 minutes after taking the drug and lasts up to four hours. Although scientists aren't exactly sure how acetaminophen-codeine works, they think codeine relieves pain by acting at special sites (receptors) in the brain that react to the body's natural painkillers (endorphins).

Side Effects and Risks

Because this drug contains a narcotic, unconsciousness or death may result from a large overdose. Signs of overdose include seizures (convulsions), nausea or vomiting, nervousness or restlessness, weakness, dizziness or drowsiness, pupils of eyes narrowed to a pinpoint, confusion, and slowed breathing. If any of the signs occurs, get emergency help immediately.

Common side effects include light-headedness or feeling faint, unusual tiredness, nausea, or drowsiness. Therefore, caution is necessary when driving or using machines.

Nausea may occur after the first couple of doses. Lie down until it passes. These side effects usually go away; however, check with your doctor if they don't go away or become bothersome.

Less commonly, you may also experience constipation, increased sweating, loss of appetite, restlessness, nightmares or unusual dreams, and trouble sleeping.

Check with your doctor as soon as possible if you experience any of the following: bloody or cloudy urine, frequent urge to urinate, mental depression, pale stools, ringing or buzzing in ears, skin rash, or yellow eyes or skin.

The acetaminophen in this medicine does not mix well with some medications that contain aspirin or other salicylates. Let your doctor know what other medications you may be taking.

After you stop taking the medicine, your body may take a while to adjust; you may have body aches, diarrhea, trouble sleeping, weakness, or rapid heartbeat. Check with your doctor if you experience these or other symptoms.

Precautions and Warnings

Alcohol and medicines that depress the central nervous system will add to the effects of this medication. Drinking alcohol also makes adverse effects of acetaminophen on the liver more likely. For both these reasons, don't drink alcohol with this medicine. Other drugs that may intensify acetaminophen-codeine effects include antihistamines, sedatives, tranquilizers or sleep medicines, other prescription pain medications, barbiturates (sedatives), seizure medicine, depression medications, and muscle relaxers. Check with your doctor if you are taking these medications.

Although there have been no reports of birth defects caused by this medicine, prolonged use during the last three months of pregnancy may cause the fetus to become addicted. Acetaminophen-codeine may also cause breathing problems in newborns if taken just before or during delivery. animal studies have shown that this drug may cause slower development of bones in the fetus. Acetaminophen-codeine is in pregnancy category C, indicating that animal studies show that the drug has some harmful effects on animal fetuses but that there has been no research in humans. The drug should be used by pregnant women only if the potential benefits justify the potential risk.