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quinidine

Pronunciation

Generic Name: quinidine (KWIH nih deen)
Brand Name: Quin-G, Cardioquin, Quinora, Quinidex Extentabs, Quinaglute Dura-Tabs, Quin-Release

What is quinidine?

Quinidine affects the way that the heart beats.

Quinidine is used to help keep the heart beating normally in people with certain heart rhythm disorders.

Quinidine may also be used for purposes not listed in this medication guide.

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

You should not take this medication if you have ever had an allergic reaction to quinidine or quinine (Qualaquin), including easy bruising or unusual bleeding. You should not take quinidine if you have myasthenia gravis or certain heart conditions, especially "AV block" (unless you have a pacemaker).

Before you take quinidine, tell your doctor if you have a slow heart rate, congestive heart failure, a serious heart condition such as "sick sinus syndrome," kidney or liver disease, low levels of potassium or magnesium in your blood, a history of "Long QT syndrome," if you are on a low-salt diet, or if you have ever had an abnormal electrocardiogram or ECG (sometimes called an EKG).

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If you need surgery, tell the surgeon ahead of time that you are using quinidine. You may need to stop using the medicine for a short time.

Ask your doctor how to adjust your quinidine dose if needed. Do not change your medication dose or schedule without your doctor's advice.

Call your doctor at once if you have a serious side effect such as: vomiting and diarrhea, ringing in the ears, hearing loss, severe dizziness, changes in vision, pain behind your eyes, white patches or cloudiness in your eyes, pale or yellowed skin, dark urine, easy bruising or bleeding, wheezing, trouble breathing, or a new or a worsening irregular heartbeat pattern.

There are many other drugs that can interact with quinidine. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor. Keep a list of all your medicines and show it to any healthcare provider who treats you.

What should I discuss with my healthcare provider before taking quinidine?

You should not take this medication if you have ever had an allergic reaction to quinidine or quinine (Qualaquin), including easy bruising or unusual bleeding. You should not take quinidine if you have myasthenia gravis or certain heart conditions, especially "AV block" (unless you have a pacemaker).

To make sure you can safely take quinidine, tell your doctor if you have any of these other conditions:

  • slow heart rate;

  • congestive heart failure;

  • a serious heart condition such as "sick sinus syndrome";

  • kidney disease;

  • liver disease;

  • low levels of potassium or magnesium in your blood;

  • a history of "Long QT syndrome";

  • if you are on a low-salt diet; or

  • if you have ever had an abnormal electrocardiogram or ECG (sometimes called an EKG).

FDA pregnancy category C. It is not known whether quinidine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Quinidine can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

How should I take quinidine?

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Your doctor may occasionally change your dose to make sure you get the best results.

Do not crush or chew an extended-release tablet. Swallow it whole. You may break the tablet in half if your doctor instructs you to.

If you need surgery, tell the surgeon ahead of time that you are using quinidine. You may need to stop using the medicine for a short time.

Ask your doctor how to adjust your quinidine dose if needed. Do not change your medication dose or schedule without your doctor's advice.

Use quinidine regularly to get the most benefit. Get your prescription refilled before you run out of medicine completely.

While using quinidine, you may need blood tests at your doctor's office. Visit your doctor regularly.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include vomiting, diarrhea, ringing in your ears or hearing problems, dizziness or spinning sensation, blurred vision, irregular heartbeat, confusion, or feeling like you might pass out.

What should I avoid while taking quinidine?

Do not change the amount of salt in your diet unless your doctor tells you to.

Grapefruit and grapefruit juice may interact with quinidine and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.

Quinidine side effects

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.

Call your doctor at once if you have a serious side effect such as:

  • vomiting and diarrhea;

  • ringing in the ears, hearing loss, severe dizziness;

  • feeling like you might pass out;

  • changes in vision, pain behind your eyes, increased sensitivity of your eyes to light;

  • white patches on your eyes;

  • cloudiness in the pupils or iris of your eyes;

  • a new or a worsening irregular heartbeat pattern;

  • pale or yellowed skin, dark colored urine, fever, confusion or weakness;

  • nausea, stomach pain, low fever, loss of appetite, clay-colored stools;

  • seizure (convulsions);

  • easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin; or

  • bronchospasm (wheezing, chest tightness, trouble breathing).

Less serious side effects may include:

  • mild nausea, vomiting, or diarrhea;

  • heartburn;

  • depressed mood;

  • muscle or joint pain;

  • headache, dizziness;

  • mild skin rash;

  • skin dryness, peeling, or flaking; or

  • flushing (warmth, redness, or tingly feeling).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

Quinidine dosing information

Usual Adult Dose for Arrhythmias:

Tablet (sulfate):100 to 600 mg/dose orally every 4 to 6 hours; begin at 200 mg/dose and titrate to desired effect (maximum daily dose: 3 to 4 g).
Extended Release: 324 to 648 mg (gluconate) orally every 8 to 12 hours or 300 to 600 mg (sulfate) orally every 8 to 12 hours.
IV: 800 mg of quinidine gluconate diluted to 50 mL and given at a rate not to exceed 1 mL/min.

Usual Adult Dose for Malaria:

Test Dose: 200 mg quinidine sulfate tablet or quinidine gluconate IM injection to determine possibility of idiosyncratic reaction.

Dosage Regimen 1:
Loading dose: 24 mg/kg of quinidine gluconate diluted in 250 mL infused over 4 hours.
Maintenance dose: Start in 24 hours, 12 mg/kg of quinidine gluconate diluted in 250 mL over 4 hours every 8 hours for 7 days or until oral therapy.

Dosage Regimen 2:
Loading dose: 10 mg/kg of quinidine gluconate diluted in 250 mL over 1 to 2 hours.
Maintenance dose: 0.02 mg/kg/min of quinidine gluconate for up to 72 hours.

Omit quinidine loading dose if patient received more than 40 mg/kg of quinine in preceding 48 hours or mefloquine within preceding 12 hours.

Change to oral quinine once parasite density is less than 1% and patient can receive oral medication to complete treatment course; total duration of treatment (quinidine/quinine): 3 days in Africa or South America; 7 days in Southeast Asia; use in combination with doxycycline, tetracycline, or clindamycin.

Usual Pediatric Dose for Malaria:

Test Dose: 200 mg quinidine sulfate tablet or quinidine gluconate IM injection to determine possibility of idiosyncratic reaction.

Dosage Regimen 1:
Loading dose: 24 mg/kg of quinidine gluconate diluted in 250 mL infused over 4 hours.
Maintenance dose: Start in 24 hours, 12 mg/kg of quinidine gluconate diluted in 250 mL over 4 hours every 8 hours for 7 days or until oral therapy.

Dosage Regimen 2:
Loading dose: 10 mg/kg of quinidine gluconate diluted in 250 mL over 1 to 2 hours.
Maintenance dose: 0.02 mg/kg/min of quinidine gluconate for up to 72 hours.

Omit quinidine loading dose if patient received more than 40 mg/kg of quinine in preceding 48 hours or mefloquine within preceding 12 hours.

Change to oral quinine once parasite density is less than 1% and patient can receive oral medication to complete treatment course; total duration of treatment (quinidine/quinine): 3 days in Africa or South America; 7 days in Southeast Asia; use in combination with doxycycline, tetracycline, or clindamycin.

What other drugs will affect quinidine?

Many drugs can interact with quinidine. Below is just a partial list. Tell your doctor if you are using:

  • cimetidine (Tagamet);

  • digoxin (Lanoxin);

  • ketoconazole (Extina, Ketozole, Nizoral, Xolegal);

  • rifampin (Rifater, Rifadin, Rifamate);

  • warfarin (Coumadin);

  • a diuretic (water pill);

  • glaucoma medication such as acetazolamide (Diamox) or methazolamide (Glauctabs, Neptazane);

  • heart or blood pressure medication such as diltiazem (Cartia, Cardizem), felodipine (Plendil), nicardipine (Cardene), nimodipine, Nimotop), nifedipine (Nifedical, Procardia), propranolol (Inderal), or verapamil (Calan, Covera, Isoptin, Verelan);

  • medicines to treat psychiatric disorders, such as haloperidol (Haldol), and others;

  • narcotic medication such as codeine or hydrocodone (Lortab, Vicodin);

  • other heart rhythm medications such as amiodarone (Cordarone, Pacerone), mexiletine (Mexitil), disopyramide (Norpace), or procainamide (Procan SR, Procanbid, Pronestyl);

  • a phenothiazine such as chlorpromazine (Thorazine), promethazine (Phenergan, Promethegan), prochlorperazine (Compazine), and others;

  • seizure medication such as phenytoin (Dilantin) or phenobarbital (Solfoton);

  • sodium bicarbonate, potassium citrate (K-Lyte, Urocit-K), sodium citrate and citric acid (Bicitra, Oracit), or sodium citrate and potassium (Citrolith, Polycitra); or

  • an antidepressant such as amitriptyline (Elavil), doxepin (Sinequan), clomipramine (Anafranil), imipramine (Tofranil), and others.

This list is not complete and there are many other drugs that can interact with quinidine. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor. Keep a list of all your medicines and show it to any healthcare provider who treats you.

Where can I get more information?

  • Your pharmacist can provide more information about quinidine.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 4.02. Revision Date: 2010-12-15, 5:01:39 PM.

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