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Nuedexta Capsules

(dextromethorphan hydrobromide and quinidine sulfate) Capsules


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, 3methoxy-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:

Dextromethorphan hydrobromide - Structural Formula Illustration

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-9-01, 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:

Quinidine sulfate - Structural Formula Illustration

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.

What are the possible side effects of dextromethorphan and quinidine (Nuedexta)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using dextromethorphan and quinidine and call your doctor at once if you have a serious side effect such as:

  • severe dizziness, fainting, fast or pounding heartbeat;
  • easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;
  • pain or burning when you urinate;
  • fever, chills, flu symptoms, nausea, vomiting, feeling...

Read All Potential Side Effects and See Pictures of Nuedexta Capsules »

What are the precautions when taking dextromethorphan hydrobromide and quinidine sulfate capsules (Nuedexta Capsules)?

Before taking this medication, tell your doctor or pharmacist if you are allergic to dextromethorphan, quinidine, quinine, or mefloquine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: blood/bone marrow disorder (such as low platelets/white blood cells/red blood cells), a certain enzyme deficiency (G6PD deficiency), kidney disease, liver disease, lupus-like syndrome, myasthenia gravis.

Quinidine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular...

Read All Potential Precautions of Nuedexta Capsules »

Last reviewed on RxList: 1/30/2015
This monograph has been modified to include the generic and brand name in many instances.

Nuedexta Capsules - User Reviews

Nuedexta Capsules User Reviews

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