Nuedexta Side Effects

Generic name: dextromethorphan / quinidine

Medically reviewed by Drugs.com. Last updated on Mar 27, 2024.

Note: This document provides detailed information about Nuedexta.

Applies to dextromethorphan / quinidine: oral capsule Side Effects associated with dextromethorphan / quinidine. Some dosage forms listed on this page may not apply specifically to the brand name Nuedexta.

Applies to dextromethorphan / quinidine: oral capsule.

Precautions

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. Blood tests may be needed to check for unwanted effects.

If your symptoms do not improve or if they become worse, check with your doctor.

Do not use this medicine together with other products containing quinidine, quinine (Qualaquin®), or mefloquine (Lariam®). You should not take this medicine if you are also using pimozide (Orap®), thioridazine (Mellaril®), or an MAO inhibitor (MAOI) such as Eldepryl®, Marplan®, Nardil®, or Parnate® within the past 14 days. Also, allow at least 14 days after stopping this medicine before starting an MAO inhibitor (MAOI).

Stop using this medicine and check with your doctor right away if you have the following symptoms while taking this medicine: black, tarry stools; bleeding gums; blood in the urine or stools; chills; fever; lightheadedness; nausea or vomiting; pinpoint red spots on the skin; or unusual bleeding or bruising.

This medicine can cause changes in heart rhythms, such as a condition called QT prolongation. It may change the way your heart beats and cause fainting or serious side effects in some patients. Contact your doctor right away if you have any symptoms of heart rhythm problems, such as fast, pounding, or irregular heartbeats.

This medicine may cause some people to become dizzy, trouble in controlling movements, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do other jobs that require you to be alert and well-coordinated.

Make sure your doctor knows about all the other medicines you are using. This medicine may cause a serious condition called serotonin syndrome when taken with medicine for depression (such as amitriptyline, clomipramine, doxepin, fluoxetine, imipramine, nortriptyline, Anafranil®, Elavil®, Prozac®, Sinequan®, or Tofranil®). Check with your doctor first before taking any other medicines.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for hay fever, allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; other medicines for seizures (e.g., barbiturates); muscle relaxants; or anesthetics, including some dental anesthetics. Check with your medical doctor or dentist before taking any of the above while you are using this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects of Nuedexta

Along with its needed effects, dextromethorphan/quinidine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking dextromethorphan / quinidine:

Get emergency help immediately if any of the following symptoms of overdose occur while taking dextromethorphan / quinidine:

Symptoms of overdose

• aggressive and violent behavior
• agitation
• blurred vision
• change in color vision
• change in consciousness
• chest pain or discomfort
• confusion
• confusion as to time, place, or person
• continuing ringing or buzzing or other unexplained noise in the ears
• decreased awareness or responsiveness
• depression
• difficulty seeing at night
• dizziness or lightheadedness
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• double vision
• excitement
• fainting
• fast, pounding, or irregular heartbeat or pulse
• feeling of constant movement of self or surroundings
• hallucinations
• hearing loss
• holding false beliefs that cannot be changed by fact
• inability to move the eyes
• increased blinking or spasms of the eyelid
• increased sensitivity of the eyes to sunlight
• irregular or slow heart rate
• loss of consciousness
• overactive reflexes
• poor coordination
• restlessness
• seeing double
• seizures
• sensation of spinning
• severe sleepiness
• shakiness and unsteady walk
• shivering
• shortness of breath
• sticking out of tongue
• sweating
• talking or acting with excitement you cannot control
• trembling or shaking
• trouble with breathing, speaking, or swallowing
• twitching
• uncontrolled eye movements
• uncontrolled twisting movements of the neck, trunk, arms, or legs
• unsteadiness, trembling, or other problems with muscle control or coordination
• unusual excitement, nervousness, or restlessness
• unusual facial expressions

Other side effects of Nuedexta

Some side effects of dextromethorphan / quinidine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to dextromethorphan / quinidine: oral capsule.

General adverse events

The most commonly reported adverse reactions (2% or greater incidence and greater than placebo) that led to treatment discontinuation were muscle spasticity, abdominal pain, asthenia, dizziness, muscle spasms, respiratory failure, and fall.^[Ref]

Gastrointestinal

• Very common (10% or more): Diarrhea (13%)
• Common (1% to 10%): Abdominal pain, vomiting, flatulence

Dextromethorphan:

• Postmarketing reports: Nausea, vomiting, stomach pain^[Ref]

Nervous system

• Very common (10% or more): Dizziness (10%)

Dextromethorphan:

• Postmarketing reports: Drowsiness, dizziness, nervousness, restlessness

Quinidine:

• Postmarketing reports: Convulsions, apprehension, ataxia, acute psychotic reactions (rare)^[Ref]

Cardiovascular

• Frequency not reported: QTc prolongation^[Ref]

Musculoskeletal

• Common (1% to 10%): Muscle spasticity, muscle spasms^[Ref]

Hepatic

• Common (1% to 10%): Increased gamma-glutamyltransferase^[Ref]

Respiratory

• Common (1% to 10%): Respiratory failure, cough^[Ref]

Other

• Common (1% to 10%): Asthenia, fall, peripheral edema

Quinidine:

• Postmarketing reports: Cinchonism^[Ref]

Cinchonism is usually a sign of chronic quinidine toxicity, but it may appear in sensitive patients after a single moderate dose of several hundred milligrams. It is characterized by nausea, vomiting, diarrhea, tinnitus headache, hearing loss, vertigo, blurred vision, diplopia, photophobia, confusion, and delirium.^[Ref]

Immunologic

• Common (1% to 10%): Influenza^[Ref]

Genitourinary

• Common (1% to 10%): Urinary tract infection^[Ref]

Ocular

Quinidine:

• Postmarketing reports: Mydriasis, disturbed color perception, night blindness, scotomata, optic neuritis, visual field loss, photosensitivity, keratopathy^[Ref]

Dermatologic

Quinidine:

• Postmarketing reports: Skin pigmentation abnormalities^[Ref]

Psychiatric

Quinidine:

• Postmarketing reports: Depression^[Ref]

See also:

Further information

Nuedexta side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer