AVP-923 is a proprietary combination of 30 mg dextromethorphan and 30 mg quinidine.

Daniel Wynn, MD, neurologist in private practice, Consultants in Neurology, Northbrook, Illinois, reported safety data in patients who received AVP-923 for 52 weeks, with an optional extension phase.

Overall, 321 patients completed at least 6 weeks of treatment, 234 completed 1 year, and 201 entered the optional extension phase (with more than 111 patients remaining on the study drug for over 2 years).

Enrolled patients had a variety of underlying diseases or conditions, such as multiple sclerosis, amyotrophic lateral sclerosis, stroke, traumatic brain injury, Parkinson's disease, Alzheimer's disease, and other dementias.

Mean duration of dosing was 258.6 days, and median compliance rate was 97.1%. The most frequently reported adverse effects during the 52-week treatment phase included nausea (23.9%), headache (22.3%), dizziness (18.8%), diarrhea (16.2%), and fatigue (13.8%).

Common adverse events were generally mild to moderate, were reported in the first week of therapy, and decreased in frequency over time.

There were no clinically important differences in the rate of adverse effects based on age (less than or greater than 65 years of age), sex, or race.

Corrected QT intervals increased slightly during treatment but these changes were small and of no clinical concern, according to the researchers.

The results suggest that AVP-923 is safe and well tolerated when administered over a 52-week period (and beyond) in patients with IEED, Dr. Wynn said.

Involuntary emotional expression disorder occurs as a result of neurological disease or brain injury. Its pathophysiology is thought to involve damage from areas of the brain that control motor output of emotions.

Hallmark symptoms are uncontrollable episodes of crying and/or laughing or related facial displays that are incongruent or exaggerated in relation to underlying mood.

There are currently no FDA-approved treatments for IEED.

The study was sponsored by Avanir Pharmaceuticals.


[Presentation title: Long-Term Safety of AVP-923 (Dextromorphan/Quinidine) in the Treatment of Involuntary Emotional Expression Disorder (IEED). Abstract P01.015]

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