Patient Education © 1998-2020 Mayo Foundation for Medical Education and Research (MFMER). It should not be used for chronic cough that occurs with smoking, asthma, or emphysema or when there is an unusually large amount of mucus or phlegm (flem) with the cough.Dextromethorphan relieves cough by acting directly on the cough center in the brain.Do not give any over-the-counter (OTC) cough and cold medicine to a baby or child under 4 years of age. Available for Android and iOS devices. It should not be used for chronic cough that occurs with smoking, asthma, or emphysema or when there is an unusually large amount of mucus or phlegm (flem) with the cough. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. Make sure you tell your doctor if you have any other medical problems, especially:Make certain your health care professional knows if you are on a low-sodium, low-sugar, or any other special diet. Dextromethorphan is in a class of medications called antitussives. Poor metabolizers of CYP2D6 may have exaggerated or prolonged effects of dextromethorphan. The client is prescribed dextromethorphan (Benylin) for treatment of a cold. Keep from freezing.Do not keep outdated medicine or medicine no longer needed.If your cough has not improved after 7 days, if sore throat has not improved after 2 days, if you have a high fever, skin rash, or continuing headache with the cough, or if asthma or high blood pressure is present, check with your doctor. Most medicines contain more than their active ingredient, and many liquid medicines contain alcohol.Use dextromethorphan only as directed by your doctor or the directions on the label. The following information includes only the average doses of dextromethorphan. Our general interest e-newsletter keeps you up to date on a wide variety of health topics.Dextromethorphan is used to relieve coughs due to colds or influenza (flu). Using these medicines in very young children might cause serious or possibly life-threatening side effects .This product is available in the following dosage forms:Portions of this document last updated: Aug. 01, 2020Copyright © 2020 IBM Watson Health. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.If you miss a dose of dextromethorphan, take it as soon as possible. Any use of this site constitutes your agreement to the Terms and Conditions and Privacy Policy linked below. We comply with the HONcode standard for trustworthy health information - If you think there has been an overdose, call your poison control center or get Dextromethorphan … Dextromethorphan will relieve a cough but will not treat the cause of the cough or speed recovery. Advertising revenue supports our not-for-profit mission.Check out these best-sellers and special offers on books and newsletters from Mayo Clinic. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.The presence of other medical problems may affect the use of dextromethorphan. These side effects may go away during treatment as your body adjusts to the medicine. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor or the label says. Follow your doctor's orders or the directions on the label. Our Health Library information does not replace the advice of a doctor. These signs may mean that you have other medical problems.Dissolve lozenges in the mouth with caution, to lessen the risk of choking.Along with its needed effects, a medicine may cause some unwanted effects. There is no specific information comparing use of dextromethorphan in the elderly with use in other age groups.Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur.