Generic name: dextromethorphan and guaifenesin [ DEX-troe-me-THOR-fan-and-gwye-FEN-e-sin ]
Other brand names of dextromethorphan and guaifenesin include Aquatab DM, Broncotron, Coricidin HBP Chest Congestion & Cough, DayQuil Mucus Control DM, Delsym Cough Plus Chest Congestion DM, ... show all 14 brands Fenesin DM IR, G-Zyncof, Mucinex DM, Phlemex, Robitussin Cough + Chest Congestion DM, Safetussin DM, Siltussin DM, TabTussin DM, Zyncof
Drug class: Expectorants

Medically reviewed by Philip Thornton, DipPharm. Last updated on Mar 25, 2025.

What is Tussin DM?

Tussin DM contains a comination of dextromethorphan and guaifenesin. Dextromethorphan is a cough suppressant and guaifenesin is an expectorant.

Tussin DM is used to treat cough and chest congestion caused by minor throat and bronchial irritations, the common cold, and allergies.

Tussin DM helps loosen phlegm (mucus) and thin bronchial secretions to help drain bronchial tubes.

Tussin DM will not treat a cough that is caused by smoking.

Warnings

Do not use Tussin DM if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.

Before taking this medicine

Do not use Tussin DM if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, and tranylcypromine.

Ask a doctor or pharmacist if this medicine is safe to use if you have:

• a cough with mucus; or

• asthma, emphysema, or chronic bronchitis.

Ask a doctor before using Tussin DM if you are pregnant or breast-feeding.

This medicine may contain phenylalanine. Check the medication label if you have phenylketonuria (PKU).

How should I take Tussin DM?

Use Tussin DM exactly as directed on the label, or as prescribed by your doctor. Cold or cough medicine is only for short-term use until your symptoms clear up.

Always follow directions on the medicine label about giving cough or cold medicine to a child. Do not use the medicine only to make a child sleepy. Death can occur from the misuse of cough or cold medicines in very young children.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

The recommended dose of Tussin DM is 10ml every 4 hours for adults and children 12 years and over. Do not take more than 6 doses in any 24-hour period. Tussin DM is not intended for use in children under 12 years of age.

Drink extra fluids to help loosen the congestion and lubricate your throat while you are taking Tussin DM.

Call your doctor if your symptoms do not improve after 7 days, or if you have a fever, rash, or headaches.

If you need to have any type of surgery, tell the surgeon ahead of time if you have taken Tussin DM within the past few days.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Since Tussin DM is used when needed, you may not be on a dosing schedule. Skip any missed dose if it's almost time for your next dose. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What to avoid

Avoid driving or hazardous activity until you know how Tussin DM will affect you. Your reactions could be impaired.

Drinking alcohol with this medicine can cause side effects.

Ask a doctor or pharmacist before using other cough or cold medicines that may contain similar ingredients.

Tussin DM side effects

Get emergency medical help if you have signs of an allergic reaction to Tussin DM: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using this medicine and call your doctor at once if you have:

• mood changes;

• severe headache; or

• severe dizziness or anxiety, feeling like you might pass out;.

Common Tussin DM side effects may include:

• dizziness, drowsiness;

• sleep problems (insomnia);

• diarrhea; or

• feeling nervous, restless, anxious, or irritable;.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

What other drugs will affect Tussin DM?

Avoid using Tussin DM with other drugs that cause drowsiness or slow your breathing (such as opioid medicine, a muscle relaxer, or medicine for anxiety or seizures).

Ask a doctor or pharmacist before using this medicine if you are also using any other drugs, including prescription and over-the-counter medicines, vitamins, and herbal products. Some medicines can cause unwanted or dangerous effects when used together. Not all possible interactions are listed in this medication guide.

Popular FAQ

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Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Tussin DM only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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