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Quinidine Tablets

What is this medication?

QUINIDINE (KWIN i deen) treats a fast or irregular heartbeat (arrhythmia). It works by slowing down overactive electric signals in the heart, which stabilizes your heart rhythm. It may also be used to treat malaria. It works by killing the parasite that causes malaria. It belongs to a group of medications called antiarrhythmics.

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This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Quinora

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Heart disease or previous heart attack
  • Kidney disease
  • Liver disease
  • Low blood pressure
  • Lung or breathing disease, like asthma
  • Myasthenia gravis
  • You have a pacemaker
  • An unusual or allergic reaction to quinidine, quinine, other medications, foods, dyes, or preservatives
  • Pregnant or trying to get pregnant
  • Breast-feeding

How should I use this medication?

Take this medication by mouth with a glass of water. Follow the directions on the prescription label. You can take this medication with or without food. Take your doses at regular intervals. Do not take your medication more often than directed. Do not stop taking this medication suddenly. This may cause serious, heart-related side effects. Your care team will tell you how much medication to take. If your care team wants you to stop the medication, the dose will be slowly lowered over time to avoid any side effects.

Talk to your care team about the use of this medication in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

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NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

Do not take this medication with any of the following:

  • Abarelix
  • Amiloride
  • Amoxapine
  • Apomorphine
  • Arsenic trioxide
  • Certain antifungal medications, such as itraconazole or ketoconazole
  • Certain quinolone antibiotics
  • Cisapride
  • Droperidol
  • Haloperidol
  • Hawthorn
  • Levomethadyl
  • Maprotiline
  • Medications for malaria, such as chloroquine and halofantrine
  • Medications for depression such as tricyclic antidepressants
  • Mefloquine
  • Methadone
  • Other medications to control heart rhythm
  • Pentamidine
  • Phenothiazines, such as chlorpromazine, mesoridazine, thioridazine
  • Pimozide
  • Ranolazine
  • Sertindole
  • Vardenafil
  • Voriconazole

This medication may also interact with the following:

  • Acetazolamide
  • Antacids
  • Barbiturates, such as phenobarbital
  • Cimetidine
  • Diuretics
  • Medications for high blood pressure or angina
  • Medications for surgery that relax muscles or block pain
  • Methazolamide
  • Phenytoin
  • Prescription pain medications, such as codeine and hydrocodone
  • Rifampin
  • Sodium bicarbonate
  • Warfarin
  • Ziprasidone

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Visit your care team for regular checks on your progress. Wear a medical ID bracelet or chain, and carry a card that describes your disease and details of your medication and dosage times.

Check your blood pressure and pulse rate regularly. Ask your care team what your blood pressure and pulse rate should be, and when you should contact them. Your care team also may schedule regular blood tests and electrocardiograms to check your progress.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medication affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medication. Avoid alcoholic drinks.

This medication can make you more sensitive to the sun. Keep out of the sun. If you cannot avoid being in the sun, wear protective clothing and use sunscreen. Do not use sun lamps or tanning beds/booths.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
  • Flushing, diarrhea, vomiting, hearing loss, ringing in the ears, dizziness, blurry vision, double vision, sensitivity to light, headache, confusion
  • Heart rhythm changes—fast or irregular heartbeat, dizziness, feeling faint or lightheaded, chest pain, trouble breathing
  • Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
  • Unusual bruising or bleeding

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Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Diarrhea
  • Dizziness
  • Fever
  • Headache
  • Nausea
  • Vomiting

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light and moisture. Keep container tightly closed. Get rid of any unused medication after the expiration date.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

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Note: Introduction and Additional Common Questions written and medically approved by Cleveland Clinic professionals.

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