Quinidine (By mouth)

Quinidine (KWIN-i-deen)

Treats irregular heartbeat (arrhythmia). Also treats malaria.

Brand Name(s):

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

You should not use this medicine if you have ever had an allergic reaction to quinidine or quinine. You should not take this medicine if you have lupus or myasthenia gravis (a muscle disease).

How to Use This Medicine:

Tablet, Capsule, Long Acting Tablet

  • Your doctor will tell you how much to take and how often.
  • Take this medicine exactly as your doctor ordered, even if you feel fine.
  • Take on an empty stomach - 1 hour before or 2 hours after meals. Your doctor may tell you to take this medicine with food or milk to avoid stomach upset.
  • Swallow the extended-release tablet whole - do not break, chew, or crush.
  • You may need to carry identification so others will know that you are taking quinidine. Ask you doctor about this.

If a dose is missed:

  • Take the missed dose as soon as you can unless you are more than 2 hours late, or 4 hours if you are taking extended-release tablets.
  • If you are more than 2 hours late (4 hours for the extended-release tablets), skip the missed dose and take the medicine at your usual time.
  • You should not use two doses at the same time.

How to Store and Dispose of This Medicine:

  • Store at room temperature, away from heat, moisture, and direct light.
  • Keep all medicine out of the reach of children.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Make sure your doctor knows if you are taking other heart medicines such as Procan®, Lanoxin®, Cordarone®, or Inderal®, blood thinners such as Coumadin®, acetazolamide (Diamox®), or pimozide (Orap®).

Warnings While Using This Medicine:

  • Check with your doctor before taking quinidine if you have blood, kidney or liver disease, asthma, an infection, psoriasis (a skin disease), or overactive thyroid.
  • Tell your doctor or dentist that you are taking quinidine before you have any kind of surgery.
  • Do not suddenly stop taking this medicine without checking with your doctor.
  • Talk with your doctor before taking quinidine if you are pregnant or breastfeeding.
  • Quinidine may make you dizzy or drowsy. Be careful if you drive a car or operate machinery.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Chest pain
  • Shortness of breath or trouble breathing
  • Blurred vision or ringing in the ears
  • Fever
  • Skin rash, severe itching or hives
  • Unusual bruising or bleeding

If you notice these less serious side effects, talk with your doctor:

  • Dizziness, lightheadedness, fainting
  • Bitter taste
  • Headache or confusion
  • Nausea or vomiting
  • Diarrhea, stomach cramps, or loss of appetite
  • Tiredness or weakness

If you notice other side effects that you think are caused by this medicine, tell your doctor

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

Last Updated: 11/6/2020

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