Quinidex

(Generic versions may still be available.)

DRUG DESCRIPTION

Quinidine is an antimalarial schizonticide and an antiarrhythmic agent with Class la activity; it is the d-isomer of quinine, and its molecular weight is 324.43. Quinidine sulfate is the sulfate salt of quinidine; its chemical name is cinchonan-9-ol, 6'-methoxy-, (9S)-, sulfate(2:1) dihydrate.

its empirical formula is (C 20 H 24 N 2 O 2 ) 2 ??· H 2 SO 4 ??·2H 2 O; and its molecular weight is 782.95, of which 82.9% is quinidine base.

Each Quinidex Extentabs® tablet contains 300 mg of quinidine sulfate (249 mg of quinidine base) in a formulation to provide extended release; the inactive ingredients are acacia, acetylated monoglycerides, calcium sulfate, carnauba wax, edible ink, FD&C Blue 2, gelatin, guar gum, magnesium oxide, magnesium stearate, polysorbates, shellac, sucrose, titanium dioxide, white wax, and other ingredients, one of which is a corn derivative. Tablets may also contain FD&C Red 40 and FD&C Yellow 6 Aluminum Lakes. These tablets comply with USP Drug Release Test 1.

What are the possible side effects of quinidine (Quinaglute Dura-Tabs, Quinidex Extentabs, Quin-Release)?

If you experience any of the following serious side effects, stop taking quinidine and seek emergency medical attention or contact your doctor immediately:

  • an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);
  • a new or a worsening irregular heartbeat pattern;
  • chest pain or chest discomfort;
  • ringing in the ears;
  • changes in vision;
  • dizziness, fainting, or headache;
  • ...

Read All Potential Side Effects and See Pictures of Quinidex »

What are the precautions when taking quinidine (Quinidex)?

Before taking quinidine, tell your doctor or pharmacist if you are allergic to it; or to quinine; 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.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: certain types of heart disease (e.g., incomplete or complete heart block without an artificial pacemaker, torsades-type irregular heartbeats, digitalis toxicity), very low blood pressure, history of easy bruising/bleeding (thrombocytopenic purpura) with use of quinine or quinidine, severe muscle weakness (myasthenia gravis).

Before using this medication,...

Read All Potential Precautions of Quinidex »


Quinidex Consumer (continued)

SIDE EFFECTS: Diarrhea, nausea, vomiting, loss of appetite, stomach pain/cramps, or a burning feeling in throat or chest (e.g., heartburn) may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Seek immediate medical attention if any of these unlikely but serious side effects occur: severe dizziness, fainting, sudden change in heartbeat (faster/slower/more irregular).

Tell your doctor immediately if any of these unlikely but serious side effects occur: vision changes, eye pain, muscle pain, unusual sweating or shakiness (signs of low blood sugar).

Tell your doctor immediately if any of these rare but very serious side effects occur: unexplained fever/signs of infection (e.g., persistent sore throat), easy bruising/bleeding, extreme tiredness, dark urine, persistent nausea/vomiting, yellowing eyes/skin, lupus-like symptoms (joint/muscle pain, chest pain, change in the amount of urine).

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

One type of reaction (cinchonism) can occur after even a single dose of this drug. Contact your doctor of pharmacist promptly if you notice symptoms such as ringing in the ears, sudden hearing problems, headache, blurred vision, confusion. Your dosage may need to be adjusted.

Certain long-acting brands of quinidine may appear as a whole tablet in the stool. This is the empty shell left after the medicine has been absorbed by the body. It is harmless.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

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

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking quinidine, tell your doctor or pharmacist if you are allergic to it; or to quinine; 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.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: certain types of heart disease (e.g., incomplete or complete heart block without an artificial pacemaker, torsades-type irregular heartbeats, digitalis toxicity), very low blood pressure, history of easy bruising/bleeding (thrombocytopenic purpura) with use of quinine or quinidine, severe muscle weakness (myasthenia gravis).

Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, liver disease, a certain blood disorder (G6PD deficiency), asthma, current infection with fever.

Quinidine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that require immediate medical attention. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm (see also Drug Interactions section). Before using quinidine, tell your doctor or pharmacist if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using quinidine safely.

This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

Before having surgery, tell your doctor that you are using this medication.

Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, elderly people may be at greater risk for serious side effects (such as dizziness) while using this drug.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This medication passes into breast milk. Consult your doctor before breast-feeding.


Quinidex Patient Information Including Side Effects

Brand Names: Quinaglute Dura-Tabs, Quinidex Extentabs, Quin-Release

Generic Name: quinidine (Pronunciation: KWIH nih deen)

  • What is quinidine (Quinidex)?
  • What are the possible side effects of quinidine (Quinidex)?
  • What is the most important information I should know about quinidine (Quinidex)?
  • What should I discuss with my healthcare provider before taking quinidine (Quinidex)?
  • How should I take quinidine (Quinidex)?
  • What happens if I miss a dose (Quinidex)?
  • What happens if I overdose (Quinidex)?
  • What should I avoid while taking quinidine (Quinidex)?
  • What other drugs will affect quinidine (Quinidex)?
  • Where can I get more information?

What is quinidine (Quinidex)?

Quinidine affects the way that the heart beats.

Quinidine is used to treat irregular heartbeat patterns.

Quinidine may also be used for purposes other than those listed in this medication guide.

What are the possible side effects of quinidine (Quinidex)?

If you experience any of the following serious side effects, stop taking quinidine and seek emergency medical attention or contact your doctor immediately:

  • an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);
  • a new or a worsening irregular heartbeat pattern;
  • chest pain or chest discomfort;
  • ringing in the ears;
  • changes in vision;
  • dizziness, fainting, or headache;
  • rash;
  • difficulty breathing;
  • abdominal pain, nausea, or vomiting; or
  • yellowing of the skin or eyes.

Other, less serious side effects may be more likely to occur. Continue to take quinidine and talk to your doctor if you experience

  • mild upset stomach;
  • headache;
  • decreased appetite;
  • diarrhea; or
  • muscle weakness.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about quinidine (Quinidex)?

Contact your doctor immediately if you experience ringing in the ears, changes in vision, dizziness, fainting, a rapid heartbeat, headache, nausea, a rash, or difficulty breathing.

Do not skip doses or change your dosing schedule without talking to your doctor. Changing your schedule could make your condition worse.

Quinidine may be taken with food to lessen stomach upset.

Do not crush, chew, or break any extended- or sustained-release formulations of quinidine. Swallow them whole. If you are not sure whether you have a long-acting form of quinidine, ask your pharmacist, nurse, or doctor.

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