Medically reviewed by A Ras MD.
What is Nuedexta used for?
Nuedexta is a prescription medicine that is used to treat sudden laughing and/or crying that happens without your control.
NUEDEXTA is an oral formulation of dextromethorphan hydrobromide USP and quinidine sulfate USP in a fixed dose combination.
Dextromethorphan hydrobromide is the pharmacologically active ingredient of NUEDEXTA that acts on the central nervous system (CNS). The chemical name is dextromethorphan hydrobromide: morphinan, 3-methoxy-17-methyl-, (9α, 13α, 14α), hydrobromide monohydrate. Dextromethorphan hydrobromide has the empirical formula C18H25NO•HBr•H2O with a molecular weight of 370.33. The structural formula is:
Quinidine sulfate is a specific inhibitor of CYP2D6-dependent oxidative metabolism used in NUEDEXTA to increase the systemic bioavailability of dextromethorphan. The chemical name is quinidine sulfate: cinchonan-9-o1, 6’-methoxy-, (9S) sulfate (2:1), (salt), dihydrate. Quinidine sulfate dihydrate has the empirical formula of (C20H24N2O2)2•H2SO4•2H2O with a molecular weight of 782.96. The structural formula is:
The combination product, NUEDEXTA, is a white to off-white powder. NUEDEXTA is available for oral use as NUEDEXTA which contains 20 mg dextromethorphan hydrobromide and 10 mg quinidine sulfate. The active ingredients are dextromethorphan hydrobromide monohydrate USP and quinidine sulfate dihydrate USP. Inactive ingredients in the capsule are croscarmellose sodium NF, microcrystalline cellulose NF, colloidal silicon dioxide NF, lactose monohydrate NF, and magnesium stearate NF.
Mechanism of Action
Dextromethorphan (DM) is a sigma-1 receptor agonist and an uncompetitive NMDA receptor antagonist. Quinidine increases plasma levels of dextromethorphan by competitively inhibiting cytochrome P450 2D6, which catalyzes a major biotransformation pathway for dextromethorphan. The mechanism by which dextromethorphan exerts therapeutic effects in patients with pseudobulbar affect is unknown.
Before taking Nuedexta, tell your doctor:
- If you are allergic to Nuedexta; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
- If you have ever had any of these health problems when taking Nuedexta, mefloquine, quinidine, or quinine: Bone marrow problems, hepatitis, low platelet count, or lupus.
- If you have any of these health problems: Low potassium or magnesium levels.
- If you have heart block or you have been told that you are at risk for heart block.
- If you have ever had a long QT on ECG or other heartbeat that is not normal.
- If you have heart failure (weak heart).
- If you are taking any of these drugs: Mefloquine, quinidine, or quinine.
- If you are taking any drugs that can cause a certain type of heartbeat that is not normal (prolonged QT interval). There are many drugs that can do this. Ask your doctor or pharmacist if you are not sure.
- If you have taken certain drugs for depression or Parkinson’s disease in the last 14 days. This includes isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline. Very high blood pressure may happen.
- If you are taking any of these drugs: Linezolid or methylene blue.
This is not a list of all drugs or health problems that interact with this medicine.
Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take Nuedexta with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
What are some things I need to know or do while I take Nuedexta?
- Tell all of your health care providers that you take Nuedexta. This includes your doctors, nurses, pharmacists, and dentists.
- Avoid driving and doing other tasks or actions that call for you to be alert until you see how Nuedexta affects you.
- To lower the chance of feeling dizzy or passing out, rise slowly if you have been sitting or lying down. Be careful going up and down stairs.
- Talk with your doctor before you drink alcohol or use other drugs and natural products that slow your actions.
- If you drink grapefruit juice or eat grapefruit often, talk with your doctor.
- This medicine can cause low platelet levels. Sometimes, very low platelet levels have led to life-threatening or deadly bleeding problems. If you have questions, talk with the doctor.
- Have blood work checked as you have been told by the doctor. Talk with the doctor.
- Myasthenia gravis may get worse while taking Nuedexta. Call the doctor if signs get worse.
- Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.
How is Nuedexta best taken?
Use Nuedexta as ordered by your doctor. Read all information given to you. Follow all instructions closely.
- Take with or without food.
- Keep taking Nuedexta as you have been told by your doctor or other health care provider, even if you feel well.
What do I do if I miss a dose?
- Take a missed dose as soon as you think about it.
- If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
- Do not take 2 doses at the same time or extra doses.
What are the side effects of Nuedexta that I need to call my doctor about immediately?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Signs of bleeding like throwing up or coughing up blood; vomit that looks like coffee grounds; blood in the urine; black, red, or tarry stools; bleeding from the gums; abnormal vaginal bleeding; bruises without a cause or that get bigger; or bleeding you cannot stop.
- Signs of lupus like a rash on the cheeks or other body parts, sunburn easy, muscle or joint pain, chest pain or shortness of breath, or swelling in the arms or legs.
- Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
- Feeling very tired or weak.
- Very upset stomach or throwing up.
- Fever or chills.
- Swollen gland.
- Swelling in the arms or legs.
- Low mood (depression).
- Change in eyesight.
- A type of abnormal heartbeat (prolonged QT interval) can happen with Nuedexta. Call your doctor right away if you have a fast heartbeat, a heartbeat that does not feel normal, or if you pass out.
- A severe and sometimes deadly problem called serotonin syndrome may happen if you take Nuedexta with certain other drugs. Call your doctor right away if you have agitation; change in balance; confusion; hallucinations; fever; fast or abnormal heartbeat; flushing; muscle twitching or stiffness; seizures; shivering or shaking; sweating a lot; severe diarrhea, upset stomach, or throwing up; or severe headache.
What are some other side effects of Nuedexta?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Throwing up.
- Feeling tired or weak.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.
If overdose is suspected:
If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
How do I store and/or throw out Nuedexta?
- Store at room temperature.
- Store in a dry place. Do not store in a bathroom.
- Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
- Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
PRINCIPAL DISPLAY PANEL
(dextromethorphan HBr and
quinidine sulfate) capsules
20 mg/ 10 mg
SRC: NLM .