Actor portrayal of patient without Pseudobulbar Affect, or PBA, crying symptoms

NUEDEXTA Side Effects

NUEDEXTA has a demonstrated safety profile. Adverse events with NUEDEXTA were generally mild to moderate in nature and consistent across studies.1

Common adverse events in the STAR Pivotal Trial1,2,a

NUEDEXTA (n=107)
Placebo (n=109)
Peripheral edema

aAdverse effects occurring in 5% or more of patients on NUEDEXTA and at two times or more the placebo rate.

Adverse effects leading to discontinuation1,2

The most commonly reported adverse reactions (incidence ≥2% and greater than placebo) that led to discontinuation of NUEDEXTA were muscle spasticity (3%), respiratory failure (1%), abdominal pain (2%), asthenia (2%), dizziness (2%), fall (1%), and muscle spasm (2%).

Risk of falls1

  • The incidence of falls with NUEDEXTA was similar to placebo; however, NUEDEXTA may cause dizziness.
  • Precautions to reduce the risk of falls should be taken, particularly for patients with motor impairment affecting gait or a history of falls.
These are not all the risks from use of NUEDEXTA. Learn More:

Adverse events in the PRISM II open-label study3,b

Reported adverse events were generally consistent with the NUEDEXTA safety profile observed in the placebo-controlled Pivotal trial.1-3

Adverse Events (N=367)b
n (%)
20 (5.4)
15 (4.1)
Urinary tract infection
10 (2.7)
9 (2.5)
6 (1.6)
6 (1.6)
5 (1.4)
5 (1.4)

bAdverse events occurring in more than 1% of patients.

NUEDEXTA Drug Interactions

NUEDEXTA may be taken with other medications, but there is a risk for adverse drug interactions. Remind your patients to talk to all their healthcare providers about any medications they are taking, including NUEDEXTA, and any side effects that they experience.

Is your patient also being treated for a mood disorder such as depression?

PBA is often comorbid with depression and other mood disorders, but PBA is a distinct condition that should be treated separately.3,6 Patients with PBA may already be on treatment for other conditions. In the PRISM II study, nearly 71% of participants (n=260) were on psychopharmacologic medications, including anticonvulsants, antipsychotics, antidepressants, sedatives/hypnotics or anxiolytics, and benzodiazepines.3

NUEDEXTA is not an antipsychotic medication and is classified as “Central Nervous System, Other” in the United States Pharmacopeia and National Formulary (USP-NF).9

When prescribing NUEDEXTA for patients with PBA, keep in mind that it should not be taken with monoamine oxidase inhibitors (MAOIs) or by patients who have taken MAOIs in the last 14 days.1 While NUEDEXTA may be taken with some selective serotonin reuptake inhibitors (SSRIs) or tricyclic antidepressants, it increases the risk for serotonin syndrome.1 For dosing precautions for SSRI paroxetine and tricyclic antidepressant desipramine, review Section 12.4 of the full prescribing information linked below.

These are not all the possible risks, drug interactions, or side effects associated with NUEDEXTA. Learn more:



NUEDEXTA Contains an Ultra-Low Dose of Quinidine.1

The daily quinidine dose (20 mg daily, 10 mg every 12 hours) in NUEDEXTA is about 3% of the lowest recommended antiarrhythmic dose.4

Chart depicting Quinidine daily dosage in NUEDEXTA of 20 mg is lower than a high antiarrhythmic dose of 1600 mg


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.

Learn about NUEDEXTA’s dosing guidelines on our Dosing and Treatment page.

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References: 1.  NUEDEXTA [package insert]. Rockville, MD: Otsuka America Pharmaceutical, Inc.  2.  Pioro EP, Brooks BR, Cummings J, et al. Dextromethorphan plus ultra-low quinidine reduces pseudobulbar affect. Ann Neurol. 2010;68(5):693-702.  3.  Hammond FM, Alexander DN, Cutler AJ, et al. PRISM II: an open-label study to assess effectiveness of dextromethorphan/quinidine for pseudobulbar affect in patients with dementia, stroke or traumatic brain injury. BMC Neurol. 2016;16:89.  4.  Grace AA, Camm AJ. Quinidine. N Engl J Med. 1998;338(1):35-45.  5.  Data on file. Avanir Pharmaceuticals, Inc.  6.  Brooks BR, Crumpacker D, Fellus J, Kantor D, Kaye RE. PRISM: a novel research tool to assess the prevalence of pseudobulbar affect symptoms across neurological conditions. PLoS ONE. 2013;8(8):e72232.  7.  Moore SR, Gresham LS, Bromberg MB, Kasarkis EJ, Smith RA. A self report measure of affective lability. J Neurol Neurosurg Psychiatry. 1997;63(1):89-93.  8.  Smith RA, Berg JE, Pope LE, Callahan JD, Wynn D, Thisted RA. Validation of the CNS emotional lability scale for pseudobulbar affect (pathological laughing and crying) in multiple sclerosis patients. Mult Scler. 2004;10(6):679-685.  9. The United States Pharmacopeia (USP). USP Medicare model guidelines v8.0. Updated February 1, 2020. Accessed June 21, 2021.

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 (