Is it safe to take Nuedexta (dextromethorphan and quinidine) and dextromethorphan 30 mg HBr (hydrobromide) together?

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From the Research

No, it is not safe to take Nuedexta (which contains dextromethorphan and quinidine) together with additional dextromethorphan 30 mg HBr. This combination would result in a dangerous double dose of dextromethorphan, which could lead to serious side effects or toxicity. Nuedexta already contains dextromethorphan (20 mg) along with quinidine (10 mg), which is specifically formulated to inhibit the metabolism of dextromethorphan, thereby increasing its concentration in the body 1. Adding another 30 mg of dextromethorphan HBr would significantly increase the risk of adverse effects such as confusion, drowsiness, dizziness, nausea, vomiting, and in severe cases, respiratory depression or serotonin syndrome 2. Some key points to consider when taking Nuedexta include:

  • The drug combination is the first treatment to be approved for pseudobulbar affect (PBA), a condition of contextually inappropriate/exaggerated emotional expression that often occurs in adults with neurological damage conditions 1
  • Dextromethorphan/quinidine at the recommended dosages of 20/10 or 30/10 mg twice daily reduced the rate of PBA episodes and improved PBA severity in a 12-week, double-blind, placebo-controlled trial in adults with ALS or MS 1
  • The drug combination was generally well tolerated in these studies, with no particular safety or tolerability concerns 1 If you are currently taking Nuedexta as prescribed by your healthcare provider, you should not take any additional over-the-counter medications containing dextromethorphan (commonly found in many cough suppressants). Always consult with your healthcare provider before combining any medications, especially those containing the same active ingredients. It is also important to note that dextromethorphan has several pharmacological mechanisms of action relevant to the brain, including being an N-methyl-D-aspartate (NMDA) receptor antagonist and a sigma-1 receptor agonist 3. However, the most recent and highest quality study 1 suggests that taking Nuedexta with additional dextromethorphan 30 mg HBr is not safe and may lead to serious side effects.

References

Research

Dextromethorphan-induced serotonin syndrome.

Clinical toxicology (Philadelphia, Pa.), 2008

Research

Dextromethorphan/quinidine sulfate for pseudobulbar affect.

Drugs of today (Barcelona, Spain : 1998), 2008

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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