Dextromethorphan-Guaifenesin
Pronounced
"gweye-FEN-eh-sin/dex-trow-meth-OR-fan"
Common brand names:
Benylin DM-E, Robitussin DM
Uses
This combination medication is used to relieve coughs caused by the common cold, bronchitis, and other breathing illnesses. Guaifenesin belongs to a class of drugs known as expectorants. It works by thinning and loosening mucus in the airways, clearing congestion, and making breathing easier. Dextromethorphan belongs to a class of drugs known as cough suppressants. It acts on a part of the brain (cough center) to reduce the urge to cough.
If you are self-treating with this medication, it is important to read the package instructions carefully before you start using this product to be sure it is right for you. (See also Precautions section.)
Cough-and-cold products have not been shown to be safe or effective in children younger than 6 years. Do not use this product to treat cold symptoms in children younger than 6 years unless specifically directed by the doctor. Some products (such as long-acting tablets/capsules) are not recommended for use in children younger than 12 years. Ask your doctor or pharmacist for more details about using your product safely.
These products do not cure or shorten the length of the common cold and may cause serious side effects. To decrease the risk for serious side effects, carefully follow all dosage directions. Do not use this product to make a child sleepy. Do not give other cough-and-cold medication that might contain the same or similar ingredients (see also Drug Interactions section). Ask the doctor or pharmacist about other ways to relieve cough and cold symptoms (such as drinking enough fluids, using a humidifier or saline nose drops/spray).
How to Use This Medication
Take this medication by mouth with or without food, as directed by your doctor. If you are self-treating, follow all directions on the product package. If you have any questions, ask your doctor or pharmacist.
Drink plenty of fluids while taking this medication. Fluids will help to break up mucus and clear congestion.
Dosage is based on your age, medical condition, and response to treatment. Do not increase your dose or take this drug more often than directed.
If you are using the liquid form of this medication, carefully measure the dose using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose.
For powder packets, empty the entire contents of the packet onto the tongue and swallow. To prevent a bitter taste, do not chew. If you are taking the capsule form, swallow the capsule whole.
Improper use of this medication (abuse) may result in serious harm (such as brain damage, seizure, death). Do not increase your dose, take it more often, or use it for a longer time than directed.
Tell your doctor if your cough returns, or if it is accompanied by a headache that doesn't go away, fever, severe sore throat, rash, or if it lasts or gets worse after 7 days. These may be signs of a serious medical problem. Get medical help right away if you think you may have a serious medical problem.
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Drug information is selected from data included with permission and copyrighted by First DataBank, Inc. This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your healthcare professional. Always seek the advice of your healthcare professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your healthcare professional. This information does not contain any assurances that this product is safe, effective or appropriate for you.
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Information expires December 2025.