Couple talking

NUEDEXTA Dosage and Administration

NUEDEXTA is the first and only FDA-approved treatment for Pseudobulbar Affect (PBA). NUEDEXTA is a combination of dextromethorphan HBr (20 mg) and quinidine sulfate (10 mg) in a capsule.1


Days 1-7

1 capsule per day
(1 capsule PO QD)

Image of one NUEDEXTA pill

Not actual size.


Beginning Day 8

2 capsules per day
(1 capsule PO Q12H)

Image of one NUEDEXTA pill
Image of one NUEDEXTA pill

Not actual size.


Titrate to 1 capsule every 12 hours on Day 8. Efficacy beyond Week 1 in the STAR Pivotal trial was achieved with Q12H dosing.2

Following this regimen, patients on NUEDEXTA had a mean 82% reduction in PBA episodes versus 45% on placebo at Week 12 in the STAR Pivotal trial.2

The need for continued treatment should be reassessed periodically as spontaneous improvement of PBA symptoms occurs in some patients. 

Specific Populations1

In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

No dose adjustments are required in patients with mild-to-moderate renal or hepatic impairment. NUEDEXTA has not been evaluated in patients with severe renal or hepatic impairment. However, increases in dextromethorphan and/or quinidine levels are likely to be observed.

NUEDEXTA's Drug Classification

NUEDEXTA is a central nervous system (CNS) agent that is categorized in the "Central Nervous System, Other" pharmacologic class in the United States Pharmacopeia and National Formulary (USP-NF).4 NUEDEXTA is not an antipsychotic medication, a psychotropic medication, nor a controlled substance.


Illustration of example NUEDEXTA prescription

Script pad is used for illustrative purposes only.

Document your diagnosis of PBA using ICD-10 code F48.2.3

Pseudobulbar Affect is a separate neurologic diagnosis — and the right diagnosis can lead to the right treatment.

Script pad is used for illustrative purposes only.

This code is intended for reference only. ICD-10-CM codes submitted to the payer must be determined by the provider/physician and accurately describe PBA as the diagnosis for which the patient receives NUEDEXTA as treatment.

NUEDEXTA Pharmacology

Video play icon over pathophysiology of PBA video
See The Pathophysiology of PBA
Learn how PBA is thought to arise in the brain of a patient with a neurologic condition or brain injury.
Download a transcript of this video.
Video play icon over pharmacology of NUEDEXTA video
See The Pharmacology of NUEDEXTA
Watch this video to learn more about the components of NUEDEXTA. The exact mechanism by which NUEDEXTA exerts its therapeutic effects in patients with PBA is unknown.1
Download a transcript of this video.

To learn more about PBA's mechanism of disease, visit PBA and the Brain.

NUEDEXTA is a combination of 2 well-characterized components1


Dextromethorphan HBr (20 mg)1,5
Nuedexta molecule dextromethorphan HBr (20mg)

An uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist and sigma-1 receptor agonist believed to modulate certain neurotransmitter functions


Quinidine sulfate (10 mg)—ultra-low dose1,6
Nuedexta molecule quinidine sulfate (10 mg)

A CYP2D6 metabolic inhibitor that increases dextromethorphan (DM) bioavailability and prolongs its elimination half-life

NUEDEXTA is believed to modulate certain neurotransmitter functions5

Dextromethorphan is thought to target glutamate signaling in two ways. The exact mechanism by which NUEDEXTA exerts its therapeutic effects in patients with PBA is unknown.1

Image of binding of Dextromethorphan to sigma-1 receptors

Binding of dextromethorphan to sigma-1 receptors is believed to result in the inhibition of glutamate release.5

Image of Dextromethorphan to NMDA receptor antagonism

NMDA is one of the main neurotransmitter receptors for glutamate. Dextromethorphan-NMDA receptor antagonism reduces postsynaptic glutamate signaling.5,7

Co-Pay Card & Sample Requests

References: 1. NUEDEXTA [package insert]. Rockville, MD: Otsuka America Pharmaceutical, Inc. 2. Data on File. Avanir Pharmaceuticals, Inc. 3. Centers for Disease Control and Prevention (CDC). International Classification of Diseases. Tenth Revision, Clinical Modification (ICD-10-CM). Accessed April 24, 2019. 4. The United States Pharmacopeial Convention (USP). Medicare Model guidelines v7.0. USP website. Accessed April 1, 2019. 5. Werling LL, Lauterbach EC, Calef U. Dextromethorphan as a potential neuroprotective agent with unique mechanisms of action. Neurologist. 2007;13(5):272-293. 6. Schadel M, Wu D, Otton SV, Kalow W, Sellers EM. Pharmacokinetics of dextromethorphan and metabolites in humans: influence of the CYP2D6 phenotype and quinidine inhibition. J Clin Psychopharmacol. 1995;15(4):263-269. 7. Pankevich DE, Davis M, Altevogt BM; for the Institute of Medicine Forum on Neuroscience and Nervous System Disorders. Glutamate-Related Biomarkers in Drug Development for Disorders of the Nervous System: Workshop Summary. Washington, DC: The National Academies Press; 2011.

INDICATION and IMPORTANT SAFETY INFORMATION for NUEDEXTA® (dextromethorphan HBr and quinidine sulfate)


NUEDEXTA is indicated for the treatment of pseudobulbar affect (PBA).

PBA occurs secondary to a variety of otherwise unrelated neurologic conditions, and is characterized by involuntary, sudden, and frequent episodes of laughing and/or crying. PBA episodes typically occur out of proportion or incongruent to the underlying emotional state. PBA is a specific condition, distinct from other types of emotional lability that may occur in patients with neurologic disease or injury.



  • Quinidine and Related Drugs: NUEDEXTA contains quinidine and should not be used concomitantly with other drugs containing quinidine, quinine, or mefloquine.
  • Hypersensitivity: NUEDEXTA is contraindicated in patients with a history of NUEDEXTA-, quinine-, mefloquine-, or quinidine-induced thrombocytopenia, hepatitis, bone-marrow depression, lupus-like syndrome, or known hypersensitivity to dextromethorphan (e.g., rash, hives).
  • MAOIs: NUEDEXTA is contraindicated in patients taking monoamine oxidase inhibitors (MAOIs), or in patients who have taken MAOIs within the preceding 14 days, due to the risk of serious and possibly fatal drug interactions, including serotonin syndrome. Allow at least 14 days after stopping NUEDEXTA before starting an MAOI.
  • Cardiovascular: NUEDEXTA is contraindicated in patients with a prolonged QT interval, congenital long QT syndrome, history suggestive of torsades de pointes, heart failure, patients receiving drugs that both prolong QT interval and are metabolized by CYP2D6 (e.g., thioridazine and pimozide), patients with complete atrioventricular (AV) block without implanted pacemaker, or at high risk of complete AV block.

Thrombocytopenia and Other Hypersensitivity Reactions: Quinidine can cause immune-mediated thrombocytopenia that can be severe or fatal. Non-specific symptoms, such as lightheadedness, chills, fever, nausea, and vomiting, can precede or occur with thrombocytopenia. NUEDEXTA should be discontinued immediately if thrombocytopenia occurs.

Hepatotoxicity: Hepatitis, including granulomatous hepatitis, has been reported in patients receiving quinidine, generally during the first few weeks of therapy. Discontinue immediately if this occurs.

Cardiac Effects: NUEDEXTA causes dose-dependent QTc prolongation. QT prolongation can cause torsades de pointes–type ventricular tachycardia, with the risk increasing as the degree of prolongation increases. When initiating NUEDEXTA in patients at risk for QT prolongation and torsades de pointes, electrocardiographic (ECG) evaluation of QT interval should be conducted at baseline and 3 to 4 hours after the first dose. Some risk factors include use with CYP3A4 inhibitors or drugs that prolong QT interval, electrolyte abnormalities, bradycardia, or left ventricular hypertrophy or dysfunction. If patients taking NUEDEXTA experience symptoms that could indicate the occurrence of cardiac arrhythmias (e.g., syncope or palpitations), NUEDEXTA should be discontinued, and the patient further evaluated.

Concomitant Use of CYP2D6 Substrates: NUEDEXTA inhibits CYP2D6 and may interact with other drugs metabolized by CYP2D6. Adjust dose of CYP2D6 substrates as needed.

Dizziness: NUEDEXTA may cause dizziness. Take precautions to reduce the risk of falls.

Serotonin Syndrome: Use of NUEDEXTA with selective serotonin reuptake inhibitors (SSRIs) or tricyclic antidepressants increases the risk of “serotonin syndrome.”

Anticholinergic Effects of Quinidine: Monitor for worsening in myasthenia gravis.

Adverse Reactions: The most common adverse reactions (incidence of ≥3% and two-fold greater than placebo) in patients taking NUEDEXTA are diarrhea, dizziness, cough, vomiting, asthenia, peripheral edema, urinary tract infection, influenza, increased gamma-glutamyltransferase, and flatulence.

These are not all the risks for use of NUEDEXTA.

To report SUSPECTED ADVERSE REACTIONS, contact Otsuka America Pharmaceutical, Inc. at 1-800-438-9927 or FDA at 1-800-FDA-1088 (