What are the side effects of Dextromethorphan (DXM)?

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Last updated: April 9, 2025View editorial policy

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From the Guidelines

Dextromethorphan can cause several side effects, ranging from mild to severe, including drowsiness, dizziness, nausea, and mild stomach discomfort, as well as more serious effects like hallucinations and dissociative effects at higher doses, as reported in various studies 1.

Common Side Effects

  • Drowsiness
  • Dizziness
  • Nausea
  • Mild stomach discomfort
  • Confusion
  • Excitability
  • Nervousness
  • Restlessness

Serious Side Effects

  • Hallucinations
  • Impaired coordination
  • Slurred speech
  • Dissociative effects similar to those of ketamine

Interactions with Other Medications

Dextromethorphan can interact with certain medications, particularly MAO inhibitors and SSRIs, potentially causing serotonin syndrome, a dangerous condition characterized by high fever, confusion, irregular heartbeat, and seizures 1.

Recommended Dosage

The recommended dosage of dextromethorphan is 10-15 mg tid or qid, with a maximum dose of 120 mg/d, as indicated in the study by Molassiotis et al. 1.

Conclusion is not allowed, so the answer will be based on the information provided and the question asked.

It is essential to stick to the recommended dosage and consult a healthcare provider if experiencing concerning side effects or taking other medications that might interact with dextromethorphan, as reported in the studies 1.

From the Research

Side Effects of Dextromethorphan

The side effects of Dextromethorphan are generally infrequent and not severe, but can include:

  • Neurological disturbances
  • Cardiovascular disturbances
  • Gastrointestinal disturbances These symptoms are usually dose-related, as indicated by the study published in 1992 2.

Safety Concerns

Particular safety concerns arise when:

  • Monoamine oxidase inhibiting (MAOI) drugs and Dextromethorphan are coadministered, as reported in the study 2
  • Episodic and sporadic abuse of Dextromethorphan occurs, which appeared to be the most significant hazard identified by analysis of spontaneous adverse event reporting 2

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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