Nuedexta - National Multiple Sclerosis Society

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About this Medication
  • Brand Name: Nuedexta (U.S.)
  • Chemical Name: dextromethorphan hydrobromide + quinidine sulfate
  • Usage in MS: Pseudobulbar Affect
  • Generic Available: No


Nuedexta is a combination of dextromethorphan hydrobromide and quinidine sulfate. The dextromethorphan acts on sigma-1 and NMDA receptors in the brain. The quinidine slows the breakdown of dextromethorphan in the body, which results in the optimal level of dextromethorphan in the brain. The exact mechanism of action of this medication is unknown.

Avanir Pharmaceuticals has been conducting trials of Nuedexta in its current and earlier formulations for several years as a treatment for pseudobulbar affect in a number of disorders, including MS and ALS. In a phase-III study published in 2010, patients diagnosed with MS or ALS who also met the diagnostic criteria for pseudobulbar affect, were randomized to receive one of two doses of Nuedexta or a placebo. The medication significantly reduced the number of episodes of pseudobulbar affect by about 47-49 percent compared to placebo. Secondary outcomes, including patient diaries and episode-free days, also suggested significant benefit among groups taking Nuedexta.

Approval by the U.S. Food and Drug Administration (FDA)

Nuedexta is approved to treat pseudobulbar affect (uncontrolled episodes of crying and or laughing that are disconnected from or out of proportion to what the person is feeling at the time) in people with multiple sclerosis and other neurological diseases.

Proper Usage

  • Before taking Nuedexta, tell your healthcare professional about all of the prescription and over-the-counter medications/supplements you are taking.
  • Before taking Nuedexta, tell your healthcare professional if you or a family member currently have or have ever had any heart disease or heart problems.
  • Ask your healthcare professional if there are any medications you cannot take while taking Nuedexta.
  • Take Nuedexta exactly as your healthcare professional tells you to take it. For the first week (days 1-7), take one capsule each morning. Beginning on day 8, take one capsule in the morning and one capsule at night – approximately 12 hours apart.
  • This medication can be taken with or without food.
  • If you miss a dose of Nuedexta, do not take 2 doses at the same time. Take your next dose at your regularly scheduled time, making sure that approximately 12 hours have passed between doses.
  • While taking Nuedexta, do not start any new medications without talking with your healthcare professional.
  • Keep this medication out of the reach of children.
  • Warnings and Precautions
  • Nuedexta can interact with other medications in ways that change the amounts of those medications or of Nuedexta in your blood. Make sure that your healthcare professional knows about all medications you are taking.
  • This medication can cause changes in your heart rhythm. Make sure that your healthcare professional knows about any heart problems you currently have or have had in the past.
  • This medication may cause dizziness. Be careful to avoid falls, particularly if you have problems with walking or balance.
  • Studies have not been done in pregnant women. However, studies in animals have shown that this medication may cause harm to a developing fetus. If you are pregnant or planning to become pregnant, be sure to discuss this with your healthcare professional.
  • Before taking Nuedexta, tell your healthcare professional if you are breast-feeding or plan to breast-feed. It is not known if Nuedexta passes into breast milk.
  • It is not known whether Nuedexta is safe or effective in children less than 18 years of age.

Possible Side Effects

  • Common side effects of Nuedexta include diarrhea, dizziness, cough, vomiting, weakness*, swelling of feet and ankles, urinary tract infection, flue, elevated liver enzymes, and gas.
  • Tell your healthcare professional immediately if you feel faint or lose consciousness after taking this medication.

For more information, call 1-855-468-3339.

*Since it may be difficult to distinguish between certain common symptoms of MS and some side effects of Nuedexta, be sure to consult your health care professional if an abrupt change of this type occurs.