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Understand How Dextromethorphan 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, different forms of this medication, and how to effectively take it to get cough relief.

Woman coughing into her arm

How Does Dextromethorphan 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

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 forms like tablets, liquids, capsules, and solutions.2 Tablets and capsules are absorbed into the digestive system, releasing the active compound into the bloodstream to calm coughing. Liquid formulations allow for precise dosing, ensuring accurate delivery of the therapeutic agent.

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.2
  • Pediatric dosage: Children aged 6to 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.2

Dextromethorphan may also be used in combination with other ingredients to tackle various cold and flu symptoms together. While this approach can be effective, it is important to talk to a healthcare provider to avoid any harmful side effects.

Clinical Efficacy and Safety Profile

Dextromethorphan's effectiveness and safety have been well-studied. While side effects are generally mild, however understanding the risk-benefit profile is important in using dextromethorphan safely.

Potential Side Effects

Dextromethorphan is safe when used as directed, however there are potential side effects individuals should be aware of. Common side effects may include: 2

  • Nausea or vomiting
  • Difficulty in urination
  • Upset stomach
  • Shakiness and unsteady walk
  • Hallucinations
  • Blurred vision
  • Dizziness
  • Confusion
  • Rapid heartbeat
  • Unusual excitement, nervousness, restlessness, or severe irritability
  • Allergic reactions such as rash or itching

Precautions for Optimal Use

To use dextromethorphan safely and effectively, remember these tips:

  • 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.2
  • Exercise caution combining with other medications: Be cautious when combining with other substances and consult a healthcare provider if you're taking multiple medications.2 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.2
  • Monitoring medical conditions: Different respiratory disorders, autoimmune disorders, and diseases can cause additional side effects. Consult with your healthcare provider before using dextromethorphan.2

Medical problems that can affect dextromethorphan usage

Medical problems that may affect dextromethorphan usage include the following:2

  • 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.
  • Diabetes: Products containing dextromethorphan can contain sugar and affect the results of blood glucose monitoring.
  • Liver Disease: Liver disease may cause dextromethorphan to build in the body and cause adverse effects.
  • Slowed breathing: Dextromethorphan can slow the rate of breathing.
  • Asthma: Dextromethorphan decreases coughing, making it harder to get rid of mucus that collects in the lungs and airways due to asthma.

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.

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.

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. 
  • Robitussin Naturals Cough are DIETARY SUPPLEMENTS. †Ivy leaf relieves occasional cough and helps clear mucus associated with hoarseness, dry throat and irritants; non-naturally derived zinc (Immune Health liquid) and vitamin C (Immune Health Gummies) support a healthy immune system; non-naturally derived melatonin for occasional sleeplessness (Sleep liquid).*
  • **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.