Codeine

Pain Relief

What is codeine?

Codeine is an opioid medicine used to treat pain. Codeine is also used to suppress cough. It is available as 15-mg, 30-mg, and 60-mg tablets. All are taken by mouth. Codeine also can be combined with other medicines, such as:

Acetaminophen (Tylenol® with codeine), to control pain (available in liquid and tablet form)
Guaifenesin, to suppress cough (available in liquid form)
Promethazine, to suppress cough (available in liquid form)

Possible side effects

Feeling drowsy
Nausea
Slower than normal rates of breathing
Low blood pressure

Symptoms of an allergic reaction include: rash, hives, itching, chills, fever, headache, muscle ache, shortness of breath, coughing, tightness in the throat, swelling of the face or neck.

Not all patients who take codeine will experience these side effects. Common side effects are bolded, but there may be others. Please report all suspected side effects to your doctor or pharmacist.

Find more information on side effects.

Possible late effects

Constipation (hard to have bowel movement)
Itching and hives
Feeling drowsy or very sleepy
Feeling dizzy
Nausea and vomiting
Mood changes (feeling sadder or happier)
Dry mouth
Fainting
Problems urinating

Tips for patients and families

Be sure to discuss all questions and instructions with your doctor or pharmacist.

If you have any of the side effects listed above, most should get better after you have taken codeine for a few of days. Tell your doctor if the side effects get worse while you are taking this medicine. It may mean you need less codeine.
If you are taking this medicine on a regular basis, do not stop taking it until the doctor tells you to do so. Stopping codeine without slowly decreasing the dose can lead to diarrhea, headache, sweating, muscle cramps, nausea, vomiting, or problems sleeping and resting.
This medicine may cause you to feel dizzy and drowsy. Do not operate heavy equipment or drive a car until you see how this medicine affects you.
If you have not slept well because of your pain, you may sleep more during the first few days of taking this medicine to “catch up” on missed sleep.
If you are taking this medicine regularly, then you should drink more fluids and eat more fiber to help prevent constipation. Tell your doctor or nurse if you have not had a bowel movement in 3 to 5 days. You may need to take a stool softener or laxative to relieve your constipation.
If you have taken codeine for a long time, at some point your doctor will slowly decrease your dose to wean you off the medicine. During this time, watch for a sudden onset of diarrhea, headache, sweating, muscle cramps, nausea, vomiting, or trouble sleeping and resting. If this occurs, call your doctor right away. It could mean your dose is being lowered too fast.
If you are taking combined drugs (codeine plus acetaminophen, guaifenesin, or promethazine), you should avoid taking other medicines that contain acetaminophen, guaifenesin, or promethazine. For example, do not take acetaminophen (Tylenol®) while taking Tylenol with Codeine®. Taking both medicines at the same time could result in a Tylenol® dose that is too high.
Other medicines can increase the drowsy feeling caused by codeine. These include:
- Alcohol (found in many over-the-counter cough and cold medicines),
- Diphenhydramine (over-the-counter Benadryl®);
- Promethazine;
- Diazepam or lorazepam;
- Antidepressants, such as amitriptyline; and
- Medicines used to treat seizures (such as carbamazepine, phenytoin, gabapentin, phenobarbital, and valproic acid).
Always tell your doctor if you are taking any of these medicines, or if you start taking any new medicine while you are taking codeine.

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Always check the medication label. Many medicines look the same. Do not take any new medicine, including over-the counter medicines or supplements, without checking with your doctor or pharmacist. Talk to your doctor or pharmacist about what to do in the case of a missed dose, allergic reaction, or medical emergency.

This information is not intended to be a complete guide and is not a substitute for talking with your provider. Medicine names, appearance, formulas, or availability may vary by clinic location. Always follow the instructions given by your care team.

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