Codeine; Guaifenesin Liquid

Codeine and guaifenesin are combined in some prescription medications to suppress your cough and break up mucus. Codeine is an opioid, with the potential to become addictive. Take this medication exactly as prescribed for as short a time as possible. Brand names include Guaiatussin AC and Guaifenesin AC.


What is this medication?

CODEINE; GUAIFENESIN (KOE deen; gwye FEN e sin) is used to relieve cough. It works by reducing cough and loosening mucus. It is a combination of an opioid cough suppressant and an expectorant.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Antituss AC, Brontex, Cheracol with Codeine, Cheratussin AC, Codefen, Dex-Tuss, Diabetic Tussin C, Duraganidin NR, ExeClear-C, Gani-Tuss NR, Guai Co, Guaiatussin AC, Guaifen C, Guiatuss AC, Halotussin AC, Iophen C-NR, M-Clear WC, Mar-Cof CG, Maxi-Tuss AC, Mytussin AC, Ninjacof-XG, RelCof C, Robafen AC, Romilar AC, Tussi-Organidin NR, Tussiden C, Tusso-C, Virtussin AC


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What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Addison's disease.
  • Brain tumor.
  • Gallbladder disease.
  • Head injury.
  • Heart disease.
  • History of irregular heartbeat.
  • History of substance use disorder.
  • If you frequently drink alcohol.
  • Kidney disease.
  • Liver disease.
  • Low blood pressure.
  • Lung or breathing disease, like asthma.
  • Mental health condition.
  • Pancreatic disease.
  • Seizures.
  • Stomach or intestine problems.
  • Thyroid disease.
  • Trouble passing urine.
  • An allergic or unusual reaction to guaifenesin, codeine, other medications, foods, dyes, or preservatives.
  • Pregnant or trying to get pregnant.
  • Breast-feeding.

How should I use this medication?

Take this medication by mouth. Follow the directions on the prescription label. You can take it with or without food. If it upsets your stomach, take it with food. Use a specially marked spoon or container to measure each dose. Ask your pharmacist if you do not have one. Household spoons are not accurate. Do not to overfill. Rinse the measuring device with water after each use. Take your medication at regular intervals. Do not take it more often than directed.

A special MedGuide will be given to you by the pharmacist with each prescription and refill. Be sure to read this information carefully each time.

Talk to your care team about the use of this medication in children. This medication is not approved for use in children.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.


What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

Do not take this medication with any of the following:

  • Alcohol.
  • Antihistamines for allergy, cough and cold.
  • Certain medications for anxiety or sleep.
  • Certain medications for depression like amitriptyline, fluoxetine, sertraline.
  • Certain medications for seizures like carbamazepine, phenobarbital, phenytoin, primidone.
  • General anesthetics like halothane, isoflurane, methoxyflurane, propofol.
  • Local anesthetics like lidocaine, pramoxine, tetracaine.
  • MAOIs like Carbex, Eldepryl, Marplan, Nardil, and Parnate.
  • Medications that relax muscles for surgery.
  • Other narcotic medications (opiates) for pain or cough.
  • Phenothiazines like chlorpromazine, mesoridazine, prochlorperazine, thioridazine.

This medication may also interact with the following:

  • Antiviral medications for HIV or AIDS.
  • Atropine.
  • Certain antibiotics like erythromycin and clarithromycin.
  • Certain medications for bladder problems like oxybutynin, tolterodine.
  • Certain medications for fungal infections like ketoconazole and itraconazole.
  • Certain medications for irregular heart beat like amiodarone, propafenone, quinidine.
  • Certain medications for Parkinson disease like benztropine, trihexyphenidyl.
  • Certain medications for stomach problems like dicyclomine, hyoscyamine.
  • Certain medications for travel sickness like scopolamine.
  • Ipratropium.
  • Rifampin.

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.


What should I watch for while using this medication?

Use exactly as directed by your care team. Do not take more than the recommended dose. You may develop tolerance to this medication if you take it for a long time. Tolerance means that you will get less cough relief with time. Tell your care team if your symptoms do not improve or if they get worse.

If you have been taking this medication for a long time, do not suddenly stop taking it because you may develop a severe reaction. Your body becomes used to the medication. This does NOT mean you are addicted. Addiction is a behavior related to getting and using a medication for a nonmedical reason. If your care team wants you to stop the medication, the dose will be slowly lowered over time to avoid any side effects.

There are different types of narcotic medications (opiates). If you take more than one type at the same time or if you are taking another medication that also causes drowsiness, you may have more side effects. Give your care team a list of all medications you use. Your care team will tell you how much medication to take. Do not take more medication than directed. Call emergency services for help if you have problems breathing or unusual sleepiness.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medication affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medication. Avoid alcoholic drinks.

The medication may cause constipation. Try to have a bowel movement at least every 2 to 3 days. If you do not have a bowel movement for 3 days, call your care team.

Your mouth may get dry. Chewing sugarless gum or sucking hard candy, and drinking plenty of water may help. Contact your care team if the problem does not go away or is severe.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat.
  • CNS depression—slow or shallow breathing, shortness of breath, feeling faint, dizziness, confusion, trouble staying awake.
  • Low adrenal gland function—nausea, vomiting, loss of appetite, unusual weakness or fatigue, dizziness.
  • Low blood pressure—dizziness, feeling faint or lightheaded, blurry vision.

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Constipation.
  • Dizziness.
  • Drowsiness.
  • Dry mouth.
  • Headache.
  • Nausea.
  • Vomiting.

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets. This medication can be abused. Keep your medication in a safe place to protect it from theft. Do not share this medication with anyone. Selling or giving away this medication is dangerous and against the law.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light.

This medication may cause harm and death if taken by other adults, children, or pets. It is important to get rid of the medication as soon as you no longer need it or it is expired. You can do this in two ways:

  • Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
  • If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put in the trash, take the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

Additional Common Questions

What is Guaiatussin AC?

Guaiatussin AC® is a brand name of a prescription medication that helps thin your mucus and relieve your cough. This medication contains two active ingredients:

  • Codeine: This is an opioid that helps you cough less. It works by reducing activity in the part of your brain that controls coughing.
  • Guaifenesin: This is an expectorant that thins your mucus so it can come out of your body more easily.

Medications like Guaiatussin AC that contain more than one active ingredient are called combination medications. That means two or more medications that sometimes work separately team up to help you. In this case, codeine and guaifenesin help suppress your cough and break up your mucus. This medication treats your symptoms but won’t treat the underlying cause (like a viral infection).

Is Guaiatussin the same as codeine?

Guaiatussin AC isn’t the same as codeine, but it does contain codeine. Providers sometimes prescribe codeine on its own, typically to treat pain when other medications aren’t working. Some medications contain codeine, as well as another active ingredient to treat multiple symptoms. Guaiatussin AC is one such example. It’s a brand name of a medication that contains both codeine (to treat cough) and guaifenesin (to thin mucus).

Is Guaifenesin AC an opioid?

Yes. Guaifenesin AC is a combination medication that contains an opioid (codeine) as one of its active ingredients. Your healthcare provider may prescribe guaifenesin AC or a similar medication to thin mucus and relieve your cough. This is typically only if other medications aren’t helping you enough.

Providers limit opioid use to the most necessary situations, as opioids can be addictive. They also prescribe the lowest dose possible for the shortest time possible. The goal is to relieve your symptoms while minimizing your risk of developing opioid dependence or opioid use disorder.

If you’re concerned about taking an opioid, be sure to talk to your provider about other options.

A note from Cleveland Clinic

When you can’t stop coughing, it can be hard to focus on anything but finding relief. Medications containing both codeine and guaifenesin are powerful and may help. But they’re only safe to use for a limited time and under the careful guidance of your healthcare provider. And they’re not for everyone.

Your medical history or other substances you’re taking may make this medication unsafe for you. It’s important to tell your provider about all other medications you’re taking, both prescription and nonprescription (over-the-counter). Also, tell them about any substances you use, like alcohol or recreational drugs. Codeine and guaifenesin can interact with other substances in dangerous ways.

Your provider will make sure this medication is safe for you to take. If it’s not, they’ll give you alternatives to treat your symptoms. Be sure to follow your provider’s instructions and ask if anything is unclear.

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Note: Introduction and Additional Common Questions written and medically approved by Cleveland Clinic professionals.

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