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Dextromethorphan, guaifenesin, and phenylephrine

Generic name: dextromethorphan, guaifenesin, and phenylephrine [ DEX-troe-meth-OR-fan, gwye-FEN-e-sin, FEN-il-EF-rin ]
Brand names: Broncotron Ped, Children Giltuss Cough and Cold, Deconex DMX, Desgen DM (Phenylephrine), Desgen Pediatric, ... show all 90 brands
Dosage forms: oral liquid (10 mg-200 mg-5 mg/15 mL; 10 mg-200 mg-5 mg/30 mL; 10 mg-200 mg-5 mg/5 mL; 15 mg-350 mg-10 mg/5 mL; 18 mg-200 mg-10 mg/15 mL; 18 mg-396 mg-10 mg/15 mL; 20 mg-200 mg-10 mg/10 mL; 20 mg-400 mg-10 mg/20 mL; 20 mg-400 mg-10 mg/5 mL; 28 mg-388 mg-10 mg/5 mL; 5 mg-100 mg-2.5 mg/5 mL; 5 mg-100 mg-2.5 mg/mL; 5 mg-50 mg-2.5 mg/5 mL; 5 mg-50 mg-2.5 mg/mL; 5 mg-75 mg-2.5 mg/5 mL), ... show all 3 dosage forms
Drug class: Upper respiratory combinations

Medically reviewed by Drugs.com on Mar 5, 2024. Written by Cerner Multum.

What is dextromethorphan, guaifenesin, and phenylephrine?

Dextromethorphan, guaifenesin, and phenylephrine is a combination medicine used to treat cough, stuffy nose, and chest congestion caused by allergies, the common cold, or the flu.

Dextromethorphan, guaifenesin, and phenylephrine may also be used for purposes not listed in this medication guide.

dextromethorphan, guaifenesin, and phenylephrine side effects

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

This medicine may cause serious side effects. Stop using this medicine and call your doctor at once if you have:

Common side effects of dextromethorphan, guaifenesin, and phenylephrine may include:

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.

Warnings

Do not use this medicine if you are using or if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, and tranylcypromine.

Before taking this medicine

Do not use this medicine if you are using or if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, and tranylcypromine.

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

This medicine may contain phenylalanine and could be harmful if you have phenylketonuria (PKU).

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

How should I take dextromethorphan, guaifenesin, and phenylephrine?

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

Your dose needs may change if you switch to a different brand, strength, or form of this medicine. Avoid medication errors by using exactly as directed on the label, or as prescribed by your doctor.

Do not give this medicine to a child without medical advice. Follow all directions when giving this medicine to a child. Do not use the medicine to make a child sleepy. Misuse of this medicine may cause death in very young children.

Swallow the tablet whole and do not crush, chew, or break it.

Measure liquid medicine with the supplied measuring device (not a kitchen spoon).

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

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

Follow the storage instructions provided with this medicine. Your pharmacist can provide more information about how to store this medicine.

What happens if I miss a dose?

dextromethorphan, guaifenesin, and phenylephrine is used when needed. If you are on a dosing schedule, skip any missed 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 should I avoid while taking dextromethorphan, guaifenesin, and phenylephrine?

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

Drinking alcohol with this medicine can cause side effects.

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

What other drugs will affect dextromethorphan, guaifenesin, and phenylephrine?

Ask a doctor or pharmacist before using any other medicines that can cause drowsiness (such as opioid medication, sleep medicine, a muscle relaxer, or medicine for anxiety or seizures). Tell your doctor about all other medicines you use. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.

Further information

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

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