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Understand How Dextromethorphan Medicine Helps Coughs

Dextromethorphan is a widely used ingredient in various over-the-counter cough medicines, known for its effectiveness in calming coughs associated with colds and the flu.1 Learn how dextromethorphan works, find different products with this medication and see how it can help relieve your cough.

Woman coughing into her arm

How Does Dextromethorphan Cough Medicine Work?

Dextromethorphan is categorized as a cough suppressant or antitussive medication. Antitussives are effective because they influence receptors in the brain that help control coughing.1 By influencing your brain receptors, it reduces activity in the cough center of your brain, decreasing cough frequency and strength.1,2

Dextromethorphan is a common ingredient in cough medicines including Robitussin. To soothe your cough symptoms for up to 4 hours, try Robitussin Elderberry Medi-Soothers to receive soothing relief from your cough, thanks to menthol and dextromethorphan in every lozenge.

How Do You Take Dextromethorphan?

You can find dextromethorphan in various cough medicine forms like syrups, tablets, liquids, capsules and solutions.1,2 While each dextromethorphan product contains the same medication, the form of the medicine can affect how quickly the drug is absorbed and how long it stays in your system.3 As a result, the drug’s effects can vary based on its inactive ingredients and form. Drug manufacturers aim to optimize both absorption and bioavailability—ensuring that a drug reaches its target site quickly and in effective amounts.

Dextromethorphan Cough Medicine Dosages

Dosages depend on the age group. Dosages for adults and children are listed below:

  • Adult dosage: Adults and adolescents over the age of 12 are recommended to have 10-20 milligrams every 4 hours as needed.4
  • Pediatric dosage: Children aged 6 to 12 are recommended to have a maximum dose of 10 mg every 4-6 hours. Children 4 to under 6 years of age are recommended to have a maximum dose of 5mg every 4 hours. Children under the age of 4 should not use dextromethorphan.4

Dextromethorphan may also be used in combination with other medicines to tackle various cold and flu symptoms together.1 However, to avoid drug interactions and overlapping treatments, consider a multisymptom product that addresses cough and other common cold and flu symptoms in one. Consult a healthcare provider if you're taking multiple medications.

Dextromethorphan’s Clinical Efficacy and Safety Profile

Dextromethorphan's effectiveness and safety have been well-studied when it comes to treating a cough.5 However, understanding the risk-benefit profile is important in using dextromethorphan products safely.

Potential Side Effects of Using Dextromethorphan

Dextromethorphan is safe when used as directed to treat a cough; however, there are potential side effects individuals should be aware of.5 Common side effects may include:1

  • Dizziness
  • Nausea
  • Vomiting
  • Stomach pain
  • Light-headedness
  • Drowsiness
  • Nervousness
  • Restlessness

Precautions for Optimal Use

To use dextromethorphan safely and effectively, remember these tips:6

  • Follow dosing instructions: Follow the dosing instructions carefully, and don't take more than directed by your healthcare provider. Exceeding the recommended dosage may cause side effects or adverse reactions.
  • Exercise caution combining with other medications: Be cautious when combining with other substances and consult a healthcare provider if you're taking multiple medications. Depending on your medication, you doctor may change your dosage, how often you use medication, or not recommend dextromethorphan.
  • Don’t consume alcohol: While using dextromethorphan, don’t consume alcohol. Alcohol may intensify side effects and impair your judgement.
  • Monitoring medical conditions: Different respiratory disorders, autoimmune disorders, and diseases can cause additional side effects. Consult with your healthcare provider before using dextromethorphan.

Medical problems that can affect dextromethorphan usage

Medical problems that may affect dextromethorphan usage include the following:

  • Chronic bronchitis, emphysema, mucus, or phlegm with cough: Bronchitis, emphysema, and phlegm with cough can cause mucus to collect in your lungs and airways. Dextromethorphan decreases coughing, which can inhibit mucus removal.1,3
  • Diabetes: Products containing dextromethorphan can contain sugar and affect the results of blood glucose monitoring.7
  • Liver Disease: Liver disease may cause dextromethorphan to build in the body and cause adverse effects.7,3
  • Asthma: Dextromethorphan decreases coughing, making it harder to get rid of mucus that collects in the lungs and airways due to asthma.1,3

It's important to talk to a healthcare provider before using dextromethorphan, especially if you have underlying medical conditions or are taking multiple medications. This ensures that the benefits of dextromethorphan are maximized while minimizing potential risks.1

By understanding how dextromethorphan works and considering its various forms and precautions, you can use it responsibly and effectively for cough relief. For other ways to find relief from cough, congestion, colds, and more, visit our Cough and Cold Center.

Robitussin Products with Dextromethorphan

Looking for soothing cough relief? Explore Robitussin’s dextromethorphan products here:

Find the best Robitussin product for your needs with our Product Finder.

Robitussin Products with Dextromethorphan and Honey

Shop Robitussin’s dextromethorphan and honey products for maximum relief:

*This product contains grade A True Source Certified Honey that’s ethically and transparently sourced. Learn more about True Source Honey.

Source Citations:

  1. Dextromethorphan. Medline Plus. https://medlineplus.gov/druginfo/meds/a682492.html. Accessed 11/03/2023.
  2. Dextromethorphan (Oral Route). Mayo Clinic. https://www.mayoclinic.org/drugs-supplements/cough-and-cold-combinations-oral-route/description/drg-20061164. Accessed 11/03/2023.
  3. Drug Absorption – Drugs. Merck Manual Consumer Version. https://www.merckmanuals.com/home/drugs/administration-and-kinetics-of-drugs/drug-absorption. Accessed 8/20/24.
  4. ROBITUSSIN® CHEST CONGESTION. NIH. https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=94455035-2482-4b27-8870-45b9b7335696&type=display. Accessed 8/20/24.
  5. Dextromethorphan Solution (Robitussin): Cough Suppressant. Cleveland Clinic. https://my.clevelandclinic.org/health/drugs/20631-dextromethorphan-solution. Accessed 8/20/24.
  6. Cough And Cold Combinations (Oral Route) Before Using. Mayo Clinic. https://www.mayoclinic.org/drugs-supplements/cough-and-cold-combinations-oral-route/before-using/drg-20061164. Accessed 8/20/24.
  7. Dextromethorphan Guaifenesin. StatPearls. NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK604212/. Accessed 8/20/24.
  8. Honey: An effective cough remedy? Mayo Clinic. https://www.mayoclinic.org/symptoms/cough/expert-answers/honey/faq-20058031. Accessed 9/17/24.

We are aware of FDA’s proposed order to remove oral phenylephrine (PE) as a nasal decongestant from the OTC monograph. Note, FDA’s proposed order does not question the safety of oral PE, only efficacy. We have introduced several new formulations across our brand portfolios, to remove oral PE, to ensure product availability for consumers to treat their symptoms ahead of the 2024/2025 cold, cough, flu season and to provide new remedies and forms to ensure people have options.

  • **True Source Honey is ethically and transparently sourced. Click here to learn more
  • ^Read more about our non-GMO standard. here
  • ⚬This product contains the active ingredients Dextromethorphan.
  • **This product contains the active ingredients Dextromethorphan and Guaifenesin.
  • *These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
  • Use as Directed.