What is this medication?

DEXTROMETHORPHAN; GUAIFENESIN (dex troe meth OR fan; gwye FEN e sin) is a combination of a cough suppressant and expectorant. It is used for the temporary relief of coughs. This medicine is also used to loosen mucus.

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

COMMON BRAND NAME(S): Altarussin DM, Aquatab DM, Cheracol D, Chest Congestion Relief DM, Delsym Children's Cough + Chest Congestion DM, Delsym Cough + Chest Congestion DM, Delsym DM Children's Cough + Chest Congestion, Dex-Tuss DM, Diabetic Tussin DM, DM/GUAI, Dometuss DM, Drituss DM, Duraganidin DM, Duratuss DM, Gani-Tuss DM NR, Genatuss DM, Geri_Tussin DM, Giltuss Children's Cough & Chest, Giltuss Diabetic Cough & Cold, Giltuss HBP Cough & Chest Congestion, Guai-Dex, Guaiasorb DM, Guiadrine DX, Guiatuss DM, H-T Tussin, Hydro-Tussin DM, Iophen DM-NR, Maxi-Tuss G, Maxi-Tuss GMX, Mucinex Children's Cough, Mucinex Children's FreeFrom Daytime Cough & Mucus, Mucinex Fast-Max DM Max, Mucus Children's Cough, Naldecon, Nalspan Senior DX, Nortuss EX, Orgadin-Tuss DM, PediaCare Cough & Congestion, Pulexn DM, Q-Tussin DM, Robafen DM, Robafen DM Clear, Robafen DM Max, Robitussin Adult Cough + Chest Congestion DM, Robitussin Adult Peak Cold, Robitussin Children's Honey Cough & Congestion DM, Robitussin Cough + Chest Congestion DM Max, Robitussin Cough and Congestion, Robitussin DM, Robitussin Honey Cough + Chest Congestion DM, Scot-Tussin Senior, Siltussin DM DAS, Siltussin-DM, Siltussin-DM Diabetic DAS-Na, Siltussin-DM Diabetic DAS-Na Maximum Strength, Simuc-DM, Su-Tuss DM, Triaminic Cough & Congestion, TRISPEC DMX, Tussi-Organidin DM NR, Tussiden DM, Tussidin DM NR, Vicks DayQuil Mucus Control DM, Vicks DayQuil Nature Fusion, Vicks Formula 44, Vicks Formula 44E, Vicks Nature Fusion Cough & Chest Congestion

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

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

•chronic bronchitis

•kidney disease

•liver disease

•lung or breathing disease, like asthma or emphysema

•unable to sit up

•an unusual or allergic reaction to dextromethorphan, guaifenesin, other medicines, foods, dyes, bromides, or preservatives

•pregnant or trying to get pregnant

•breast-feeding

How should I use this medication?

Take this medicine by mouth with a full glass of water. Follow the directions on the prescription label. Use a specially marked spoon or container to measure your dose. Household spoons are not accurate. Take your medicine at regular intervals. Do not take it more often than directed.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

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 medicine with any of the following medications:

•MAOIs like Carbex, Eldepryl, Marplan, Nardil, and Parnate

•procarbazine

This medicine may also interact with the following medications:

•other medicines for colds or allergy

•medicines for depression or other mental disturbances

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?

Do not treat yourself for a cough for more than 1 week without consulting your doctor or health care professional. If you have a high fever, skin rash, lasting headache, or sore throat, see your doctor.

Drink 6 to 8 glasses of water daily while you are taking this medicine to help loosen mucus.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine 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 medicine. Avoid alcoholic drinks.

What side effects may I notice from receiving this medication?

Side effects that you should report to your doctor or health care professional as soon as possible:

•allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue

•breathing problems

•confusion

•excitement, nervousness, restlessness, or irritability

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

•headache

•stomach upset

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.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Keep bottle tightly closed. Throw away any unused medicine after the expiration date.

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.

What is Mucinex DM®?

Mucinex DM is a brand-name medication that may relieve chest congestion and stop your cough. It may temporarily ease these symptoms when you have an infection like a common cold or flu. But it won’t clear up the infection any faster. It also won’t stop you from spreading germs to others.

Mucinex DM contains these two active ingredients:

• Guaifenesin. This is an expectorant. It thins mucus in your airways so you can cough it up more easily. Getting rid of this mucus can help ease chest congestion.
• Dextromethorphan. This is a cough suppressant. It calms your cough reflex to help suppress (stop) your cough.

You should talk to a healthcare provider before taking Mucinex DM or any over-the-counter (OTC) medication. They’ll make sure it’s safe for you based on your medical history and any other medications or supplements you’re taking right now. You should also read the drug label and closely follow the dosing instructions. If you’re not sure about something, ask your provider.

What is the DM for on Mucinex?

The DM stands for dextromethorphan. It’s a cough suppressant, and it’s one of the two active ingredients in Mucinex DM (the other is guaifenesin, an expectorant).

What is the difference between Mucinex DM and just Mucinex®?

Mucinex DM and Mucinex (without the DM) both contain guaifenesin, an expectorant that thins your mucus. But Mucinex DM also contains dextromethorphan, a cough suppressant. Mucinex DM will thin your mucus so it’s easier to get it out, but it’ll also calm your cough reflex. This may help if your cough is making it hard to focus during the day or sleep at night. Mucinex (guaifenesin) works best if you’re also drinking a lot of water — this also helps to thin out the secretions.

Mucinex (without the DM) doesn’t contain dextromethorphan. So, it’ll thin mucus to ease chest congestion, but it won’t stop you from coughing.

You may also see Mucinex D® on the store shelf. This product contains guaifenesin and pseudoephedrine. Pseudoephedrine acts as a nasal decongestant, so it’ll temporarily clear up your stuffy nose. However, U.S. law requires all medicines containing pseudoephedrine to be sold behind the counter. That means you need to ask a store employee for it and show your photo ID before buying. This law is in place to help prevent pseudoephedrine misuse.

In addition to federal regulations, some states place specific limits on how much pseudoephedrine you can buy within a month or a year. You may want to check the laws in your area before you purchase medications containing this drug.

Mucinex and Mucinex DM are both sold over the counter, without the need to show your ID. That’s because they don’t contain pseudoephedrine.

Does Mucinex DM make you sleepy?

Drowsiness is a possible side effect of Mucinex DM and other medications containing dextromethorphan. Don’t drive while taking this medication until you’re aware of how it affects your ability to stay awake and focus.

Talk to your provider about any side effects that you experience. They may suggest other medications or even home remedies, like honey, to soothe your cough.

A note from Cleveland Clinic

When mucus takes up residence in your chest, it can be hard to clear your throat, talk or even just focus. Throw a cough into the mix, and there goes your hope of getting anything done — let alone sleeping.

Medications that combine dextromethorphan and guaifenesin may help you. But all medications come with their own possible side effects and risks. And what’s safe for someone you know might not be safe for you. Talk to your healthcare provider about what’s right for you before you pick anything up at the store.

Note: Intro and FAQ sections written and reviewed by Cleveland Clinic professionals.