treatment icon


Dr Karen Martin
Reviewed by Dr Karen MartinReviewed on 19.10.2023 | 4 minutes read

Dextromethorphan is a cough medication used to relieve dry and tickly coughs. You can buy it from your pharmacy either on its own or in combination with other medications for colds and flu. There are various products available. Examples include Robitussin DM, Nyquil, and many others.

Doctor’s advice

Who is it for?

In the US, dextromethorphan is available over the counter in various formulations, such as syrups, tablets, and lozenges, and is commonly used to relieve cough symptoms associated with colds and respiratory infections. It is generally considered safe for adults and children over the age of 12, but specific age recommendations may vary depending on the product and its formulation.

Dextromethorphan works by suppressing the cough reflex in the brain, providing relief from persistent or irritating coughing. It is often found in combination with other active ingredients, such as expectorants or antihistamines, to provide comprehensive relief from cough symptoms.

When using dextromethorphan or any cough medication, it is essential to follow the recommended dosage instructions provided on the product label or as directed by your healthcare professional.

It's important to note that dextromethorphan should not be used in children under 12 years old unless specifically instructed by a healthcare provider. Additionally, individuals with certain medical conditions, such as asthma, chronic bronchitis, or liver disease, should consult a pharmacist or doctor before using dextromethorphan to ensure it is safe and appropriate for their condition.

Overall, dextromethorphan can provide effective relief from cough symptoms when used appropriately and according to the recommended guidelines. However, it is essential to use caution and seek medical advice if you have any concerns about its use or if cough symptoms persist or worsen.

How does it work?

Dextromethorphan is a commonly used cough suppressant medication that works by acting on the brain's cough center to reduce the urge to cough. It belongs to a class of drugs known as antitussives, specifically opioid-like cough suppressants, although it does not have the same addictive or analgesic properties as opioids.

The exact mechanism of how dextromethorphan suppresses coughing is not fully understood, but it is believed to involve multiple pathways in the brain. One proposed mechanism is that dextromethorphan acts as an NMDA receptor antagonist, blocking the activity of N-methyl-D-aspartate (NMDA) receptors involved in transmitting cough signals in the brain.

It's important to note that dextromethorphan is considered safe and effective when used as directed for short-term relief of cough symptoms associated with colds, flu, or respiratory infections. However, misuse or overuse of dextromethorphan can lead to adverse effects, including dizziness, drowsiness, nausea, and respiratory depression.

As with any medication, it's essential to follow the recommended dosage instructions provided on the product label or as directed by a healthcare professional. Using dextromethorphan inappropriately or exceeding the recommended dosage can increase the risk of side effects and may not provide additional benefits in managing cough symptoms. If cough symptoms persist or worsen despite treatment with dextromethorphan, it's advisable to seek medical advice for further evaluation and management.

Should anyone avoid taking it?

Do not take dextromethorphan if you are allergic to the medication, or another ingredient listed in the product. Children under 12 years should not take dextromethorphan.

If you avoid ingesting alcohol in any form, please note that some dextromethorphan products do contain small amounts of alcohol used in their production.

Speak with your doctor or pharmacist before taking dextromethorphan if you:

  • are pregnant or breastfeeding
  • have liver or kidney problems
  • are diabetic
  • have respiratory conditions such as asthma or COPD

as the medication may not be suitable for you. If you take any prescription, over-the-counter or herbal medicines, ask your doctor or pharmacist to check if they are safe to take alongside dextromethorphan.

Are there any side effects?

As with all medications, some people may experience side effects. These can include nausea and vomiting, constipation, drowsiness, dizziness, and confusion. If dextromethorphan makes you feel drowsy, you should avoid driving or working. Also, it is best to avoid drinking alcohol when taking the medication, as it can worsen your side effects.

Dextromethorphan can cause dependence if you take it for too long. If you are dependent on dextromethorphan, you will feel unwell when you go without the medication – you should speak with your doctor or pharmacist if you are concerned about this or any specific side effects.

Was this helpful?

Was this helpful?

This article has been written by UK-based doctors and pharmacists, so some advice may not apply to US users and some suggested treatments may not be available. For more information, please see our T&Cs.
Dr Karen Martin
Reviewed by Dr Karen Martin
Reviewed on 19.10.2023
App Store
Google Play
Piff tick
Version 2.26.5
© 2024 Healthwords Ltd. All Rights Reserved