Acetaminophen and Codeine Phosphate

acetaminophen - codeine

By Roxane Laboratories

What side effects are possible with this medication?

A side effect is an unwanted response to a medication when it is taken in normal doses and cannot be anticipated. It can be mild or severe, temporary or permanent, but does not occur in everyone.

The following side effects have been reported by at least 1% of people taking this medication. If you develop any of these side effects (or any other side effects not listed here) or they change in intensity, speak to your doctor or pharmacist for advice on managing them and on the risks and benefits of the medication.

  • abdominal pain
  • constipation
  • dizziness
  • drowsiness
  • itching
  • lightheadedness
  • nausea
  • rash
  • shortness of breath
  • vomiting

At higher doses, codeine can cause respiratory depression. Respiratory depression is a decreased breathing rate, which prevents the body from getting enough oxygen.

Click here to learn about serious side effects that can potentially occur with any medication. These examples are provided for information purposes only and are not meant to be exhaustive. Always consult your doctor for sound medical advice specific to your particular medication and treatment.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online or by phone at 1-800-332-1088.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.


January 13, 2011

The FDA has issued new information concerning the use of prescription acetaminophen products. To read the full FDA Advisory, visit the FDA's web site at

Alcohol use: If you drink alcohol, talk to your doctor about the risk of liver damage related to acetaminophen and how to use this medication safely.

Allergic reactions: This medication contains sodium metabisulfite, a sulfite that may cause allergic-type reactions including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. The overall prevalence of sulfite sensitivity in the general population is unknown and probably low. Sulfite sensitivity is seen more frequently in asthmatic than in nonasthmatic people. If you have any symptoms of an allergic reaction (e.g., swelling of the face, mouth, and throat, difficulty breathing, itching, rash, or vomiting), contact your doctor or seek medical assistance immediately.

Dependence and withdrawal: Physical dependence, psychological dependence, and abuse have occurred with the use of this medication. People with a history of past or current substance use problems may be at greater risk of developing abuse or addiction while taking this medication. Abuse is not a problem with people who require this medication for pain relief. Withdrawal symptoms may occur if this medication is stopped suddenly. Talk to your doctor about the risks and benefits of taking this medication.

Drowsiness/reduced alertness: Codeine may impair mental or physical abilities. Do not drive a car or perform hazardous tasks until you are sure that this medication does not impair your ability to perform these tasks safely.

Medical conditions: Discuss with their doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed if you are a senior, are debilitated, or have any of the following conditions:

  • an acute abdominal condition
  • Addison's disease
  • enlarged prostate
  • a head injury
  • hypothyroidism
  • increased pressure in the head
  • kidney disease
  • liver disease
  • low thyroid
  • urethral stricture

Other products containing acetaminophen: This medication contains acetaminophen. Acetaminophen can cause liver damage if the recommended dose is exceeded. Avoid other medications containing acetaminophen, such as cough and cold products, while you are using acetaminophen - codeine. Check the label of all medications you take to see if they contain acetaminophen.

Skin: This medication has been associated with serious skin reactions including exfoliative dermatitis, Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). If you notice symptoms including a rash, itching, blistering, or peeling skin, stop taking this medication and contact your doctor right away.

Ultra-rapid metabolizers: Some people have a variation in a liver enzyme and change codeine into morphine more rapidly and completely than other people. These people are ultra-rapid metabolizers and are more likely to have higher-than-normal levels of morphine in their blood after taking codeine, which can result in overdose symptoms such as extreme sleepiness, confusion, or shallow breathing. In most cases, it is unknown if someone is an ultra-rapid codeine metabolizer. If you have symptoms such as extreme sleepiness, confusion, or shallow breathing, contact your doctor or get medical attention right away.

Worsening symptoms: If redness or swelling occurs in the area of pain, if symptoms do not improve or worsen, or if new symptoms develop (e.g., high fever, rash, itching, persistent headache) while you are taking this medication, contact your doctor as soon as possible. These may be signs of other conditions that require medical attention.

Pregnancy and newborns: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately. Dependency and withdrawal signs have been reported in newborns whose mothers took opiates such as codeine regularly during pregnancy. These signs include irritability, excessive crying, tremors, fever, vomiting, and diarrhea. Signs usually appear during the first few days of life.

Breast-feeding: Acetaminophen and codeine pass into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding. Some breast-feeding mothers taking codeine can have higher morphine levels in their breast milk if they are ultra-rapid metabolizers. These higher levels of morphine in breast milk may lead to life-threatening or fatal side effects in nursing babies. Watch for signs of morphine toxicity in your baby including increased sleepiness (more than usual), difficulty breast-feeding, breathing difficulties, or limpness. Call the baby's doctor immediately if you notice these signs. If you cannot reach the doctor right away, take the baby to an emergency room or call 9-1-1 (or local emergency services).

Children: The safety and effectiveness of using this medication have not been established for children under 12 years of age.

Seniors: Seniors may have a higher risk of side effects from this medication. Some seniors may require a lower dosage of this medication.

What other drugs could interact with this medication?

There may an interaction between acetaminophen - codeine and any of the following:

  • alcohol
  • antianxiety agents (e.g., clonazepam, lorazepam)
  • anticoagulants (blood thinners, e.g., warfarin)
  • antipsychotics (e.g., clozapine, haloperidol, risperidone)
  • chlordiazepoxide
  • cholestyramine
  • fluoxetine
  • imatinib
  • lopinavir
  • narcotic analgesics (e.g., morphine, oxycodone)
  • other products containing acetaminophen or codeine
  • other sedating agents (e.g., barbiturates, sedatives, sleeping pills, anaesthetics)
  • paroxetine
  • ritonavir
  • terbinafine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

<< Previous Page

The contents of this health site are for informational purposes only. Always seek the advice of your physician or other qualified healthcare provider regarding any questions you may have about a medical condition.

Email Bookmark Feedback Add to Print
We recommend the following articles

Make it stop!

Stressed? Feel a headache coming on? Need relief? There's more you can do than just grab for... more >>


Cancel OK