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Brand Name(s) : Benylin Dry Coughs, Robitussin Dry Cough Medicine, Boots Dry Cough Relief Lozenges, Vicks Cough Lozenges
Side Effects


Dextromethorphan should be used with caution in: patients with a long-term cough or asthma; patients with liver problems; patients who have a cough which produces lots of mucus (phlegm); patients suffering from alcoholism (some liquid formulations contain alcohol); patients who have an intolerance to some sugars.

It should not be used in: patients who are allergic to dextromethorphan or any of the ingredients; patients who are wheezing or having an asthma attack; patients who are taking, or have taken in the last two weeks, drugs for depression known as monoamine oxidase inhibitors (MAOIs); patients taking any other cough and cold medicine; children under age of 6 or 12 years (depending on the brand).

Also see list of precautions and interactions.


Store below 25°C or 30°C (depending on the brand).


What is it used for?

  • Dextromethorphan is used to help stop coughing.
  • It is a member of a group of drugs called anti-tussives, sometimes known as cough suppressants. Cough and cold preparations containing dextromethorphan should not be given to children under 6 years, as there is no evidence that they work and can cause side effects.
  • In general this drug is used to relieve dry and tickly coughs that do not produce any mucus (phlegm).
  • Benefits of being on this drug can include decreasing or stopping you coughing.

Listed below are the typical uses of dextromethorphan:

  • Relief of dry, tickly cough (does not produce any mucus (phlegm)) which is usually associated with the common cold

On occasion your doctor may prescribe this medicine to treat a condition not on the above list.


How often do I take it?

  • This medication is available to take by mouth as lozenges and as a liquid.
  • The liquid is usually taken up to fours times daily, with or without food.
  • Lozenges may need to be taken more or less frequently. Consult the patient information leaflet for details.
  • Use this medication regularly in order to get the most benefit from it.
  • Remember to use it at the same time each day - unless specifically told not to by your doctor.
  • It may take about one hour before the full benefit of this drug takes effect.
  • Certain medical conditions may require different dosage instructions as directed by your doctor.

What dose?

  • Dosage is based on your age, gender, medical condition, response to therapy, and use of certain interacting medicines.

Do I need to avoid anything?

  • Dextromethorphan is not known to affect the ability to drive or operate machinery.

When can I stop?

  • Stop taking the medication when you feel better. If symptoms persist or worsen, talk to your doctor.


If any of these persist or you consider them severe then inform your doctor or pharmacist.

Tell your doctor immediately if you develop any of the following symptoms: sudden wheeziness; difficulty in breathing.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

The Yellow Card Scheme allows you to report suspected side effects from any type of medicine (which includes vaccines, herbals and over the counter medicines) that you are taking. It is run by the medicines safety watchdog called the Medicines and Healthcare products Regulatory agency (MHRA). Please report any suspected side effect on the Yellow Card Scheme website.


Before taking dextromethorphan, tell your doctor or pharmacist if you are allergic to it; or to other anti-tussives; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist in case of: an asthma attack

Before using this medication tell your doctor or pharmacist your medical history, especially any of the following: liver problems; long-term cough or asthma; a cough which produces lots of mucus (phlegm); alcoholism; an intolerance to some sugars.

Before having surgery, tell your doctor or dentist that you are taking this medication.

Does alcohol intake affect this drug?

  • Limit the amount of alcohol you drink, as it may increase the drug side effects, such as dizziness and drowsiness.

The elderly: there is no need to alter the adult dose of dextromethorphan for the elderly.

Pregnancy and breastfeeding - please ensure you read the detailed information below


The safety of dextromethorphan has not been established during pregnancy. Ask your doctor or pharmacist if you have any doubts or questions about this.

It is sensible to limit use of medication during pregnancy whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.


It is not known whether dextromethorphan passes into breast-milk. Ask your doctor or pharmacist if you have any questions about this.

It is sensible to limit use of medication during breastfeeding whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.


Before using this medicine, tell your prescriber of all the medicines you are taking including prescription medicines and medicines you have bought over the counter without a prescription. Tell your prescriber if you are taking vitamins or complementary remedies such as herbal products, as these can also interact with medicines.

If you are taking more than one medicine, these may interact with each other. Your prescriber may decide to use medicines which interact with each other if the benefit outweighs the risks. In these cases, the dose of your medicines may need to be adjusted or you may be monitored more closely.

The following medicines may interact with dextromethorphan:

This information does not contain all possible interactions. Therefore, tell your prescriber of all the products you are using before taking this medicine.

If you have a question or want to discuss anything about your medicine, speak to your local pharmacist.


Taking too much dextromethorphan may cause the following: nausea, drowsiness, restlessness, excitement, ataxia (inability to coordinate muscle movements) and breathing problems.

People who have taken too much dextromethorphan should tell a doctor or go to a hospital casualty department straight away.

If you think you, or someone you care for, might have accidentally taken more than the recommended dose of dextromethorphan or intentional overdose is suspected, contact your local hospital, GP or if in England call 111. In Scotland call NHS 24. In Wales, call NHS Direct Wales. In the case of medical emergencies, always dial 999.


If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

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Source: Selected from data included with permission and copyrighted by Boots UK Limited. This copyrighted material is sourced from a licensed data provider and is not for distribution, except as may be authorised by the applicable terms of use.
CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgement of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse events, nor should it be construed to indicate that use of a particular medicine is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any medicine, changing any diet, or discontinuing any course of treatment.

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