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Guaifenesin and Dextromethorphan


Related terms
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    Related terms
    • Brand Names: U.S.: Cheracol® D [OTC];Cheracol® Plus [OTC];Coricidin HBP® Chest Congestion and Cough [OTC];Diabetic Siltussin-DM DAS-Na Maximum Strength [OTC];Diabetic Siltussin-DM DAS-Na [OTC];Diabetic Tussin® DM Maximum Strength [OTC];Diabetic Tussin® DM [OTC];Double Tussin DM [OTC];Fenesin DM IR [OTC];Guaicon DMS [OTC];Iophen DM-NR [OTC];Kolephrin® GG/DM [OTC];Mucinex® DM Maximum Strength [OTC];Mucinex® DM [OTC];Mucinex® Kid's Cough Mini-MeltsT [OTC];Mucinex® Kid's Cough [OTC];Q-Tussin DM [OTC];RefenesenT DM [OTC];Robafen DM Clear [OTC];Robafen DM [OTC];Robitussin® Peak Cold Cough + Chest Congestion DM [OTC];Robitussin® Peak Cold Maximum Strength Cough + Chest Congestion DM [OTC];Robitussin® Peak Cold Sugar-Free Cough + Chest Congestion DM [OTC];Safe Tussin® DM [OTC];Scot-Tussin® Senior [OTC];Silexin [OTC];Siltussin DM DAS [OTC];Siltussin DM [OTC];Vicks® 44E [OTC];Vicks® DayQuil® Mucus Control DM [OTC];Vicks® Nature FusionT Cough & Chest Congestion [OTC];Vicks® Pediatric Formula 44E [OTC]
    • Brand Names: Canada: Balminil DM E;Benylin® DM-E

    • It is used to thin mucous so it can be taken from the body by coughing.
    • Guaifenesin thins fluids in the lungs.
    • Dextromethorphan works on the cough center in the brain.


    How to take

    • Take with a full glass of water.
    • Drink lots of noncaffeine liquids unless told to drink less liquid by your doctor.
    • Long-acting products: Swallow whole. Do not chew, break, or crush.
    • There is a liquid (syrup) if you cannot swallow pills.
    • Those who have feeding tubes may also use the liquid. Flush the feeding tube before and after this drug is given.

    Missed Dose

    • Take a missed dose as soon as you think about it.
    • If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
    • Do not take 2 doses at the same time or extra doses.
    • Many times this drug is taken on an as needed basis.


    • Store at room temperature.
    • Protect capsules and tablets from water. Do not store in a bathroom or kitchen.



    • Talk with the doctor before giving this drug to a child. Check all of your child's drugs, including OTC, with doctor.
    • Sometimes drugs are not safe when you take them with certain other drugs. Taking them together can cause bad side effects. This is one of those drugs. Be sure to talk to your doctor about all the drugs you take.


    • If you have an allergy to guaifenesin, dextromethorphan, or any other part of this drug.
    • Tell your doctor if you are allergic to any drugs. Make sure to tell about the allergy and what signs you had. This includes telling about rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
    • If you have taken isocarboxazid, phenelzine, or tranylcypromine in the last 14 days. Monoamine oxidase inhibitors (eg, isocarboxazid, phenelzine, and tranylcypromine) must be stopped 14 days before this drug is started. Taking both at the same time could cause risky high blood pressure.


    • This drug is not for coughs due to smoking or lung disease.
    • If you have PKU, talk with your doctor. Some products have phenylalanine.
    • Check all drugs you are taking with your doctor. This drug may not mix well with some other drugs.
    • Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
    • Tell your doctor if you are pregnant or plan on getting pregnant.
    • Tell your doctor if you are breast-feeding.

    Side Effects

    • Feeling dizzy. Rise slowly over a few minutes when sitting or lying down. Be careful climbing.
    • Headache.
    • Upset stomach or throwing up. Many small meals, good mouth care, sucking hard, sugar-free candy, or chewing sugar-free gum may help.

    Contact a healthcare provider

    • If you think there was an overdose, call your local poison control center or ER right away.
    • Signs of a very bad reaction to the drug. These include wheezing; chest tightness; fever; itching; bad cough; blue or gray skin color; seizures; or swelling of face, lips, tongue, or throat.
    • Cough that does not go away.
    • Any rash.
    • Side effect or health problem is not better or you are feeling worse.

    General Statements

    • If you have a very bad allergy, wear an allergy ID at all times.
    • Do not share your drugs with others and do not take anyone else's drugs.
    • Keep all drugs out of the reach of children and pets.
    • Most drugs may be thrown away in household trash after mixing with coffee grounds or kitty litter and sealing in a plastic bag.
    • In Canada, take any unused drugs to the pharmacy. Also, visit to learn about the right way to get rid of unused drugs.
    • Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
    • Call your doctor for help with any side effects. If in the U.S., you may also call the FDA at 1-800-FDA-1088 or if in Canada, you may also call Health Canada's Vigilance Program at 1-866-234-2345.
    • Talk with the doctor before starting any new drug, including OTC, natural products, or vitamins.

    Author information
    • Copyright © 1978-2013 Lexi-Comp Inc. All rights reserved.

    Copyright © 2011 Natural Standard (

    The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.