Dextromethorphan/Quinidine, Oral deks-troh-meth-OR-fan KWIN-ih-deen

What are other names for this medicine?

Type of medicine: pseudobulbar affect (PBA) treatment

Generic and brand names: dextromethorphan hydrobromide and quinidine sulfate, oral; Nuedexta

What is this medicine used for?

This medicine is taken by mouth to treat involuntary, sudden, and frequent episodes of laughing or crying in people with certain conditions that affect the brain. This medicine has not been shown to be safe or effective in treating symptoms caused by other conditions, such as Alzheimer’s or other kinds of dementia.

It may be used for other conditions as determined by your healthcare provider.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have ever had:

• an allergic reaction to any medicine
• a bleeding disorder
• a stroke
• heart disease or heart failure
• high blood pressure
• kidney problems
• liver problems
• long QT syndrome (problems with electrical activity in the heart muscle) or if you have a close relative who has long QT syndrome
• myasthenia gravis
• problems with alcohol or drug abuse
• problems with low potassium or magnesium levels in your blood

Do not take this medicine if you have taken an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl, Emsam), and tranylcypromine (Parnate) within the last 14 days. Also, do not take this medicine if you are also taking quinidine, quinine, mefloquine, or certain antipsychotic medicines such as thioridazine or pimozide (Orap). Using these medicines together can cause very serious side effects. Tell your healthcare provider about ALL the medicines you are taking.

Females of childbearing age: Tell your healthcare provider if you are pregnant or plan to become pregnant. It is not known whether this medicine will harm an unborn baby. Do not breast-feed while taking this medicine without your healthcare provider's approval.

How do I take it?

Check the label on the medicine for directions about your specific dose. Take this medicine exactly as your healthcare provider prescribes. Do not take more or take it longer than prescribed.

This medicine is usually taken by mouth as 1 capsule once a day for the first 7 days, then increased to 1 capsule twice a day thereafter. Do not take more than 2 capsules in a 24-hour period. Make sure there is about 12 hours between doses.

You may take this medicine with or without food.

What if I miss a dose?

If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. Do not take more than 2 tablets in a 24-hour period. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What if I overdose?

If you or anyone else has intentionally taken too much of this medicine, call 911 or go to the emergency room right away. If you pass out, have seizures, weakness or confusion, or have trouble breathing, call 911. If you think that you or anyone else may have taken too much of this medicine, call the poison control center. Do this even if there are no signs of discomfort or poisoning. The poison control center number is 800-222-1222.

Symptoms of an acute overdose may include: nausea, vomiting, diarrhea, dizziness, headache, confusion, blurred or double vision, ringing in the ears, fast or irregular heartbeat, trouble breathing or walking, seizures, coma.

What should I watch out for?

This medicine may cause serotonin syndrome, which can be life-threatening. It may be caused by taking this medicine with other medicines. These medicines include antidepressants, medicines to treat migraines, pain medicines, some cough medicines, St. John's wort, and others. Make sure that your providers know ALL of the medicines that you take.

Contact your healthcare provider right away if you have:

• restlessness
• loss of coordination
• fast heart beat
• rapid changes in blood pressure
• increased body temperature
• nausea
• vomiting
• diarrhea

This medicine may cause drowsiness, dizziness, or blurred vision. Do not drive or operate machinery unless you are fully alert and can see clearly. Be careful to avoid falling, especially if you currently have trouble walking or a history of falls.

This medicine increases the effects of alcohol and other drugs that slow down your nervous system. Do not drink alcohol or take other medicines unless your healthcare provider approves. You may need to have regular checkups and blood tests to see how this medicine affects you. Keep all appointments.

If you need emergency care, surgery, or dental work, tell the healthcare provider or dentist you are taking this medicine.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away. If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives; itching; rash; trouble breathing; tightness in your chest; swelling of your lips, tongue, and throat), irregular or rapid heartbeat, chest pain.

Serious (report these to your healthcare provider right away): Unusual bruising or bleeding, fever, cough, ringing in your ears, hearing loss, blurred vision, delirium, depression, dark colored urine or pale stools, yellow eyes or skin, severe stomach pain, severe dizziness or fainting, muscle or joint pain; swelling in hands, ankles, or feet; changes in urination or painful urination.

Other: Headache, weakness, heartburn, nausea, dizziness, drowsiness, diarrhea, vomiting, nervousness, muscle spasms.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your healthcare provider if you are taking:

• amiloride
• amphetamines such as dextroamphetamine (Dexedrine) and methamphetamine (Desoxyn)
• antacids (take them 2 hours apart from doses of this medicine)
• antibiotics such as ciprofloxacin (Cipro), clarithromycin (Biaxin), erythromycin (Ery-Tabs, E.E.S.), isoniazid, levofloxacin (Levaquin), linezolid (Zyvox), moxifloxacin (Avelox), pentamidine (NebuPent), rifampin (Rifadin, Rimactane), and telithromycin (Ketek)
• anticancer medicine such as crizotinib (Xalkori), imatinib (Gleevec), nilotinib (Tasigna), procarbazine (Matulane), vandetanib (Caprelsa), and vemurafenib (Zelboraf)
• antidepressants such as amitriptyline, desipramine (Norpramin), doxepin, duloxetine (Cymbalta), fluoxetine (Prozac), fluvoxamine, imipramine (Tofranil), nefazodone, nortriptyline (Pamelor), paroxetine (Paxil), and vilazodone (Viibryd)
• antifungals such as fluconazole (Diflucan), itraconazole (Sporanox), ketoconazole (Nizoral), posaconazole (Noxafil), and voriconazole (VFEND)
• antipsychotic medicines such as aripiprazole (Abilify), chlorpromazine, haloperidol (Haldol), pimozide (Orap), risperidone (Risperdal), quetiapine (Seroquel), thioridazine, and ziprasidone (Geodon)
• antiseizure medicines such as carbamazepine (Tegretol), phenytoin (Dilantin), and primidone (Mysoline)
• aprepitant (Emend)
• arsenic trioxide (Trisenox)
• atomoxetine (Strattera)
• barbiturates such as butabarbital (Butisol), pentobarbital (Nembutal), and phenobarbital
• beta blockers such as acebutolol (Sectral), atenolol (Tenormin), carvedilol (Coreg), labetalol (Trandate), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), pindolol, propranolol (Inderal LA), and sotalol (Betapace)
• cimetidine (Tagamet)
• conivaptan (Vaprisol)
• cyclosporine (Sandimmune, Gengraf, Neoral)
• dextromethorphan, an ingredient in many cough and cold medicines such as Robitussin-DM
• heart medicines such as amiodarone (Pacerone, Cordarone), digoxin (Lanoxin), diltiazem (Cardizem, Cartia, Dilacor, Tiamate, Tiazac), disopyramide (Norpace), dofetilide (Tikosyn), dronedarone (Multaq), flecainide (Tambocor), propafenone (Rythmol), mexiletine (Mexitil), nifedipine (Procardia), procainamide, quinidine, sotalol (Betapace), and verapamil (Calan, Isoptin, Verelan)
• MAO inhibitor antidepressants such as isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl, Emsam), and tranylcypromine (Parnate) (Do not take this medicine and an MAO inhibitor within 14 days of each other.)
• medicines to treat HIV such as atazanavir (Reyataz), delavirdine (Rescriptor), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), nevirapine (Viramune), ritonavir (Norvir), and saquinavir (Invirase)
• medicines to treat malaria such as chloroquine (Aralen), mefloquine, and quinine (Qualaquin)
• medicines to treat migraine headaches, such as almotriptan (Axert), dihydroergotamine (D.H.E. 45, Migranal), eletriptan (Relpax), ergotamine (Cafergot, Ergomar) frovatriptan (Frova), naratriptan (Amerge), rizatriptan (Maxalt), sumatriptan (Imitrex, Alsuma, Sumavel), and zolmitriptan (Zomig)
• memantine (Namenda)
• pain medicine such as codeine, hydrocodone (Vicodin, Lortab), methadone (Dolophine, Methadose), and tramadol (Ultram)
• St. John's wort
• warfarin (Coumadin)

Many more drugs may interact with this medicine. Be sure that you tell your healthcare provider about all other medicines you are taking, especially those prescribed by other healthcare providers.

Do not drink alcohol while taking this medicine unless your healthcare provider approves.

The effects of this medicine may be increased if you take it with grapefruit juice. Talk with your healthcare provider about this.

If you are not sure if your medicines might interact, ask your pharmacist or healthcare provider. Keep a list of all your medicines with you. List all the prescription medicines, nonprescription medicines, supplements, natural remedies, and vitamins that you take. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.