Oct 29, 2010 The first drug specifically developed to treat uncontrollable laughing or crying, also called pseudobulbar affect, or PBA, has been approved by the U.S. Food and Drug Administration. Nuedexta™ (dextromethorphan hydrobromide and quinidine sulfate, formerly called AVP-923, Avanir Pharmaceuticals) is an oral therapy shown in clinical trials to significantly reduce episodes in people with MS, ALS and other disorders. Comment: “This FDA approval represents a significant step forward for people who live with the debilitating effects of pseudobulbar affect,” said Dr. Nicholas LaRocca, Vice President of Healthcare Delivery and Policy Research at the National MS Society. “For people who experience unexplained bouts of inappropriate laughing or crying, this new therapy has the potential to substantially help both them and their families.” Background: It is currently estimated that approximately 10% of persons with MS experience episodes of uncontrollable laughing and/or crying that are unpredictable and seem to have little or no relationship to actual events or the individual’s actual feelings. This condition, which also affects people with other neurological conditions, is thought to result from lesions – damaged areas – in emotional pathways in the brain. It is important for family members and caregivers to know this, and realize that people who experience these episodes may not always be able to control their expression of emotions. Until now, no medication was approved specifically to treat this condition. 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. Nuedexta is a patented, orally-administered combination of dextromethorphan and an enzyme inhibitor known as quinidine. Quinidine slows down the breakdown of dextromethorphan in the body, which results in a sustained elevation of dextromethorphan in the brain. In 2006, Avanir received a letter from the FDA indicating that the drug was “approvable” and requesting that additional studies be conducted, leading to the phase III study that was recently published. ( Annals of Neurology , published online September 13, 2010). Results of that study suggested that the drug significantly reduced the rate 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. Read more Safety: According to the approved prescribing information, Nuedexta may cause serious side effects including changes in heart rhythm, and is not recommended (contraindicated) for people who have certain types of heart conditions unless they have an implanted pacemaker. The most common adverse reactions in patients taking Nuedexta capsules are diarrhea, dizziness, cough, vomiting, weakness, swelling of feet and ankles, urinary tract infection, flu, elevated liver enzymes, and flatulence. Since Nuedexta may cause dizziness, precautions to reduce the risk of falls should be taken, particularly for those with motor impairment affecting gait or a history of falls. Drug Interactions: Nuedexta can interact with other medications causing significant changes in blood levels of those medications and/or Nuedexta. Nuedexta is contraindicated in patients receiving drugs that both prolong QT interval (part of heart function) and are metabolized by CYP2D6 (e.g., thioridazine and pimozide) and should not be used concomitantly with other drugs containing quinidine, quinine, or mefloquine. Nuedexta is contraindicated in patients taking monoamine oxidase inhibitors (MAOIs – a class of antidepressant drugs such as Marplan, Nardil or Parnate) or in patients who have taken MAOIs within the preceding 14 days. For additional important about the use and safety about Nuedexta, please see the full Prescribing Information at http://www.nuedexta.com./ . Read more about MS and emotional changes. A Clinical Bulletin for physicians , providing details about pseudobulbar affect and its treatment in MS, is available on the National MS Society’s Professional Resource Center.