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Guaifenesin

(gwye fen' e sin)

Why is this medication prescribed?   Return to top

Guaifenesin is used to make a cough more productive when caused by colds, bronchitis, or other lung infections. Guaifenesin should not be used to treat children younger than 2 years of age because it may cause serious or life-threatening side effects in young children. Guaifenesin extended-release tablets should not be used in children younger than 12 years old. Other guaifenesin products should be used carefully and only as directed on the package label in children 2-12 years old. Guaifenesin will relieve symptoms but will not treat the cause of symptoms or speed recovery. Guaifenesin is in a class of medications called expectorants. It works by thinning the mucus in the air passages to make it easier to cough up the mucus and clear the airways.

How should this medicine be used?   Return to top

Guaifenesin comes as a tablet, a capsule, an extended-release (long-acting) tablet, dissolving granules, and a syrup (liquid) to take by mouth. The tablets, capsules, dissolving granules, and syrup are usually taken with or without food every 4 hours as needed The extended-release tablet is usually taken with or without food every 12 hours. Follow the directions on the package or on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take guaifenesin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Guaifenesin comes alone and in combination with antihistamines, cough suppressants, and decongestants. Ask your doctor or pharmacist for advice on which product is best for your symptoms. Check nonprescription cough and cold product labels carefully before using two or more products at the same time. These products may contain the same active ingredient(s) and taking them together could cause you to receive an overdose. This is especially important if you will be giving cough and cold medications to a child.

Swallow the extend-release tablets whole with a full glass of water. do not break, crush, or chew them.

If you are taking the dissolving granules, empty the entire contents of the packet onto your tongue and swallow.

If you are taking the liquid, do not use a household spoon to measure your dose. Use the measuring spoon or cup that came with the medication or use a spoon made especially for measuring medication.

If your symptoms do not improve within 7 days or if you also have a high fever, a rash, or a headache that does not go away, call your doctor.

Other uses for this medicine   Return to top

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?   Return to top

Before taking guaifenesin,

• tell your doctor and pharmacist if you are allergic to guaifenesin, any other medications, or any of the ingredients in the guaifenesin product you plan to take. Check the package label for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take.
• tell your doctor if you smoke and if you have or have ever had a cough that occurs with a large amount of phlegm (mucus) or if you have or have ever had a breathing problem such as asthma, emphysema, or chronic bronchitis. If you will be taking the dissolving granules, tell your doctor if you are on a low magnesium diet or if you have kidney disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking guaifenesin, call your doctor.
• if you have phenylketonuria (PKU, a inherited condition in which a special diet must be followed to prevent mental retardation), you should know that the dissolving granules may be sweetened with aspartame, a source of phenylalanine.

What special dietary instructions should I follow?   Return to top

Drink plenty of fluids while you are taking this medication.

Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?   Return to top

Guaifenesin is usually taken as needed. If your doctor has told you to take guaifenesin regularly, take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?   Return to top

Guaifenesin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• headache
• nausea
• vomiting

Guaifenesin may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.

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 [at http://www.fda.gov/MedWatch/index.html] or by phone [1-800-332-1088].

What storage conditions are needed for this medicine?   Return to top

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose   Return to top

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know?   Return to top

Ask your pharmacist any questions you have about guaifenesin.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names   Return to top

Brand names of combination products   Return to top

Last Revised - 03/01/2008
Last Reviewed - 04/01/2000

American Society of Health-System Pharmacists, Inc. Disclaimer

The MedMaster™ Patient Drug Information database provides information copyrighted by the American Society of Health-System Pharmacists, Inc., Bethesda, Maryland Copyright© 2008. All Rights Reserved.

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