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Dexbrompheniramine, dextromethorphan, and phenylephrine

Generic name: dexbrompheniramine, dextromethorphan, and phenylephrine [ dex-brom-feh-NEER-a-meen, dex-tro-meh-THOR-fan, and-feh-nill-EFF-rin ]
Brand names: Alahist CF, Alahist DM (dexbrompheniramine), Brantussin DM, Panatuss Pediatric DXP, Polytussin DM Liquid, ... show all 13 brands
Dosage forms: oral liquid (0.5 mg-5 mg-2.5 mg/mL; 1 mg-10 mg-5 mg/mL; 2 mg-15 mg-7.5 mg/5 mL), oral tablet (2 mg-20 mg-10 mg)
Drug class: Upper respiratory combinations

Medically reviewed by Drugs.com on Aug 2, 2023. Written by Cerner Multum.

What is dexbrompheniramine, dextromethorphan, and phenylephrine?

Dexbrompheniramine is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose.

Dextromethorphan is a cough suppressant. It affects the signals in the brain that trigger cough reflex.

Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).

Dexbrompheniramine, dextromethorphan, and phenylephrine is a combination medicine used to treat runny or stuffy nose, sneezing, itching, watery eyes, cough, and sinus congestion caused by allergies, the common cold, or the flu.

dexbrompheniramine, dextromethorphan, and phenylephrine will not treat a cough that is caused by smoking, asthma, or emphysema.

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

Dexbrompheniramine, dextromethorphan, 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 dexbrompheniramine, dextromethorphan, 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 dexbrompheniramine, dextromethorphan, and phenylephrine if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.

Do not use cough or cold medicine to make a child sleepy.

Before taking this medicine

You should not use this medicine if you are allergic to dexbrompheniramine, dextromethorphan, or phenylephrine.

Do not use cough or cold medicine if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include furazolidone, isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, and tranylcypromine.

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

Ask a doctor before using this medicine if you are pregnant or breast-feeding.

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

How should I take dexbrompheniramine, dextromethorphan, 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 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).

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

If you need surgery or medical tests, tell the surgeon or doctor if you have taken a cough or cold medicine within the past few days.

Store at room temperature away from moisture and heat. Do not freeze.

Dexbrompheniramine, dextromethorphan, and phenylephrine dosing information

Usual Adult Dose for Cough and Nasal Congestion:

Dexbrompheniramine 2 mg/dextromethorphan 20 mg/phenylephrine 10 mg/5 mL oral syrup:
5 mL orally 4 times daily.

Dexbrompheniramine 6 mg/dextromethorphan 30 mg/phenylephrine 20 mg oral tablets, extended release:
1 tablet orally 2 times daily not to exceed 2 tablets daily.

Usual Pediatric Dose for Cough and Nasal Congestion:

Dexbrompheniramine 2 mg/dextromethorphan 20 mg/phenylephrine 10 mg/5 mL oral syrup:
>=6 yrs to <12 yrs: 2.5 mL orally 4 times daily.
>=12 yrs: 5 mL orally 4 times daily.

Dexbrompheniramine 6 mg/dextromethorphan 30 mg/phenylephrine 20 mg oral tablets, extended release:
>=6 yrs to <12 yrs: 0.5 tablet orally 2 times daily not to exceed 1 tablet daily.
>=12 yrs: 1 tablet orally 2 times daily not to exceed 2 tablets daily.

What happens if I miss a dose?

Since dexbrompheniramine, dextromethorphan, and phenylephrine 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 should I avoid while taking dexbrompheniramine, dextromethorphan, and phenylephrine?

Drinking alcohol with dexbrompheniramine, dextromethorphan, and phenylephrine can cause side effects.

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

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

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

Avoid using this medicine 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 any other medication, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed in this medication guide.

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.