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Dextromethorphan and quinidine (Oral route)

Pronunciation:

dex-troe-meth-OR-fan hye-droe-BROE-mide, KWIN-i-deen SUL-fate

Brand Names:

  • Nuedexta

Dosage Forms:

  • Capsule

Classifications:

Therapeutic—

Central Nervous System Agent

Chemical—

Quinidine

Uses of This Medicine:

Dextromethorphan and quinidine combination is used to treat a rare condition called pseudobulbar affect (PBA) or emotional incontinence. PBA is a nervous system disorder that is characterized by uncontrollable, sudden, and frequent episodes of crying or laughing.

This medicine is available only with your doctor's prescription.

Before Using This Medicine:

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies—

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Children—

Appropriate studies have not been performed on the relationship of age to the effects of dextromethorphan and quinidine combination in the pediatric population. Safety and efficacy have not been established.

Older adults—

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of dextromethorphan and quinidine combination in the elderly.

Pregnancy—

Pregnancy CategoryExplanation
All TrimestersCAnimal studies have shown an adverse effect and there are no adequate studies in pregnant women OR no animal studies have been conducted and there are no adequate studies in pregnant women.

Breast-feeding—

Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.

Other medicines—

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Amifampridine
  • Aurothioglucose
  • Bepridil
  • Cisapride
  • Clorgyline
  • Dronedarone
  • Fingolimod
  • Grepafloxacin
  • Iproniazid
  • Isocarboxazid
  • Itraconazole
  • Ketoconazole
  • Levomethadyl
  • Mesoridazine
  • Mifepristone
  • Moclobemide
  • Nelfinavir
  • Nialamide
  • Pargyline
  • Phenelzine
  • Pimozide
  • Piperaquine
  • Posaconazole
  • Procarbazine
  • Rasagiline
  • Ritonavir
  • Saquinavir
  • Selegiline
  • Sparfloxacin
  • Terfenadine
  • Thioridazine
  • Tipranavir
  • Toloxatone
  • Tranylcypromine
  • Voriconazole
  • Ziprasidone

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Acetazolamide
  • Afatinib
  • Ajmaline
  • Alefacept
  • Alfuzosin
  • Almotriptan
  • Amiodarone
  • Amitriptyline
  • Amoxapine
  • Amprenavir
  • Apomorphine
  • Aprindine
  • Arbutamine
  • Arsenic Trioxide
  • Artemether
  • Asenapine
  • Astemizole
  • Atazanavir
  • Atracurium
  • Azithromycin
  • Bedaquiline
  • Boceprevir
  • Bupropion
  • Carbamazepine
  • Chloral Hydrate
  • Chloroquine
  • Ciprofloxacin
  • Citalopram
  • Clarithromycin
  • Clomipramine
  • Clozapine
  • Cobicistat
  • Colchicine
  • Crizotinib
  • Cyclobenzaprine
  • Dabigatran Etexilate
  • Dabrafenib
  • Darunavir
  • Dasatinib
  • Decamethonium
  • Delavirdine
  • Desipramine
  • Desvenlafaxine
  • Digitoxin
  • Digoxin
  • Disopyramide
  • Dofetilide
  • Dolasetron
  • Domperidone
  • Doxepin
  • Doxorubicin
  • Doxorubicin Hydrochloride Liposome
  • Droperidol
  • Duloxetine
  • Enflurane
  • Enzalutamide
  • Erythromycin
  • Escitalopram
  • Eslicarbazepine Acetate
  • Etravirine
  • Everolimus
  • Fentanyl
  • Flecainide
  • Fluconazole
  • Fluoxetine
  • Fluvoxamine
  • Formoterol
  • Fosamprenavir
  • Foscarnet
  • Gatifloxacin
  • Gemifloxacin
  • Granisetron
  • Halofantrine
  • Haloperidol
  • Halothane
  • Hydroquinidine
  • Hydroxytryptophan
  • Ibutilide
  • Imipramine
  • Infliximab
  • Isoflurane
  • Isradipine
  • Ivabradine
  • Lanreotide
  • Lapatinib
  • Levofloxacin
  • Levomilnacipran
  • Lidocaine
  • Lidoflazine
  • Linezolid
  • Lomitapide
  • Lopinavir
  • Lorcainide
  • Lorcaserin
  • Lumefantrine
  • Mefloquine
  • Methadone
  • Mexiletine
  • Milnacipran
  • Mitotane
  • Moxifloxacin
  • Nalidixic Acid
  • Nilotinib
  • Norfloxacin
  • Nortriptyline
  • Octreotide
  • Ofloxacin
  • Ondansetron
  • Paliperidone
  • Pancuronium
  • Paroxetine
  • Pasireotide
  • Pazopanib
  • Pentamidine
  • Perflutren Lipid Microsphere
  • Pirmenol
  • Pixantrone
  • Pomalidomide
  • Prajmaline
  • Prilocaine
  • Primidone
  • Probucol
  • Procainamide
  • Prochlorperazine
  • Propafenone
  • Protriptyline
  • Quetiapine
  • Quinidine
  • Quinine
  • Ranolazine
  • Romidepsin
  • Salmeterol
  • Sertraline
  • Sibutramine
  • Simeprevir
  • Sodium Phosphate
  • Sodium Phosphate, Dibasic
  • Sodium Phosphate, Monobasic
  • Solifenacin
  • Sorafenib
  • Sotalol
  • Spiramycin
  • Succinylcholine
  • Sulfamethoxazole
  • Sunitinib
  • Telaprevir
  • Telavancin
  • Telithromycin
  • Tetrabenazine
  • Tizanidine
  • Tocophersolan
  • Toremifene
  • Trabectedin
  • Tramadol
  • Trazodone
  • Trifluoperazine
  • Trimethoprim
  • Trimipramine
  • Tubocurarine
  • Ulipristal
  • Vandetanib
  • Vardenafil
  • Vasopressin
  • Vecuronium
  • Vemurafenib
  • Venlafaxine
  • Vilanterol
  • Vincristine
  • Vincristine Sulfate Liposome
  • Vinflunine
  • Vortioxetine
  • Zolmitriptan

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Abarelix
  • Abiraterone Acetate
  • Amiloride
  • Aripiprazole
  • Atenolol
  • Cimetidine
  • Clobazam
  • Dalfopristin
  • Dextromethorphan
  • Dicumarol
  • Fosphenytoin
  • Galantamine
  • Haloperidol
  • Magaldrate
  • Magnesium Carbonate
  • Magnesium Hydroxide
  • Magnesium Oxide
  • Magnesium Trisilicate
  • Nifedipine
  • Nisoldipine
  • Paroxetine
  • Phenobarbital
  • Phenytoin
  • Propranolol
  • Quinidine
  • Quinupristin
  • Rifapentine
  • Timolol
  • Tolterodine
  • Tramadol
  • Vemurafenib
  • Verapamil

Other interactions—

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

  • Grapefruit Juice

Other medical problems—

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Bone marrow problems caused by quinidine, quinine, or mefloquine, history of or
  • Heart block without a pacemaker or
  • Heart failure or
  • Heart rhythm problems (e.g., congenital long QT syndrome, prolonged QT interval, or a history of torsade de pointes) or
  • Hepatitis caused by quinidine, quinine, or mefloquine, history of or
  • Lupus-like syndrome caused by quinidine, quinine, or mefloquine, history of or
  • Thrombocytopenia (low platelets in the blood) caused by quinidine, quinine, or mefloquine, history of—Should not be used in patients with these conditions.
  • Drug abuse or dependence, or history of—Dependence may be more likely to develop.
  • Heart or blood vessel disease or
  • Hypokalemia (low potassium in the blood) or
  • Hypomagnesemia (low magnesium in the blood) or
  • Hypertension (high blood pressure) or
  • Stroke, history of—May increase risk for more serious side effects.
  • Kidney disease, severe or
  • Liver disease, severe—Higher blood levels of this medicine can occur, which increases the risk of serious side effects.
  • Myasthenia gravis (severe muscle weakness)—Use with caution. May make this condition worse.

Proper Use of This Medicine:

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of side effects.

Grapefruits and grapefruit juice may increase the effects of dextromethorphan and quinidine combination by increasing the amount of this medicine in your body. You should not eat grapefruit or drink grapefruit juice while you are taking this medicine.

Dosing—

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (capsules):
    • For PBA or emotional incontinence:
      • Adults—One capsule once a day for the first 7 days of treatment. Then on day 8 and onwards, dose should be two capsules per day, taken as one capsule every 12 hours. Each capsule contains 20 milligrams (mg) of dextromethorphan and 10 mg of quinidine.
      • Children—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions While Using This Medicine:

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.

Side Effects of This Medicine:

Along with its needed effects, a medicine 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:

Less common
Bladder pain
bloating or swelling of the face, arms, hands, lower legs, or feet
bloody or cloudy urine
chills
cough
diarrhea
difficult, burning, or painful urination
fever
frequent urge to urinate
general feeling of discomfort or illness
headache
joint pain
loss of appetite
lower back or side pain
muscle aches and pains
nausea
rapid weight gain
runny nose
shivering
sore throat
sweating
tingling of the hands or feet
trouble sleeping
unusual tiredness or weakness
unusual weight gain or loss
vomiting

Get emergency help immediately if any of the following symptoms of overdose occur:

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

Some side effects 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:

Less common
Bloated
excess air or gas in the stomach or intestines
full feeling
lack or loss of strength
passing gas

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.


Last Updated: 4/4/2014

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