Safety and Efficacy of AVP-923 in PBA Patients With ALS or MS

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

Objectives of the study are to evaluate the safety, tolerability, and efficacy of two different doses of AVP-923 (capsules containing either 30 mg of dextromethorphan hydrobromide and 10 mg of quinidine sulfate \[AVP-923-30\] or 20 mg of dextromethorphan hydrobromide and 10 mg of quinidine sulfate \[AVP-923-20\]) when compared to placebo, for the treatment of PBA in a population of patients with amyotrophic lateral sclerosis (ALS) or multiple sclerosis (MS) over a 12-week period. An additional objective is to determine the pharmacokinetic parameters of the two different doses of AVP-923 in a subset of the study population. Pseudobulbar Affect (PBA) is a condition characterized by involuntary, sudden and frequent episodes of laughing and/or crying out of proportion or incongruous to the underlying emotion of happiness or sadness Other terms used to describe this condition include emotional lability, emotionalism, emotional incontinence, emotional discontrol, excessive emotionalism, and pathological laughing and crying. The outbursts can occur spontaneously or in response to provocative stimuli such as questions or events. A body of evidence suggests that PBA can be modulated through pharmacologic intervention. Dextromethorphan (DM) is a low-affinity uncompetitive antagonist of the N-Methyl-D-aspartate (NMDA) receptor, reducing the level of excitatory activity. DM also acts at the phencyclidine-binding site, which is part of the NMDA receptor complex. DM is a sigma receptor agonist, suppressing the release of excitatory neurotransmitters. Quinidine (Q) is a known potent inhibitor of cytochrome P450 2D6 (CYP2D6), that decreases the metabolism of dextromethorphan and helps to achieve sustained and therapeutic levels of this drug.

About this trial record page

What this page shows

Public field values for ClinicalTrials.gov record NCT00573443, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.

What this page does not do

No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.

Where the data comes from

Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.

Last refresh

Last update posted Apr 12, 2017 · Synced Oct 21, 2026

Related: full search, browse by condition, browse by drug or therapy, browse by sponsor, browse by U.S. city.