Quinidine Oral (patient information)

IMPORTANT WARNING

Studies have shown that some antiarrhythmic drugs may increase the risk of death, especially if you have had a previous heart attack. This information also may apply to quinidine. Quinidine usually is used only to treat life-threatening arrhythmias.

Why this medication is prescribed

Quinidine is used to treat abnormal heart rhythms. It works by making your heart more resistant to abnormal activity. Quinidine is also used to treat malaria.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

How this medication should be used

Quinidine comes as a tablet to take by mouth. Immediate-acting quinidine usually is taken three or four times a day. The extended-release (long-acting) product usually is taken two or three times a day. Do not cut, crush, or chew extended-release tablets; swallow them whole.

Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take quinidine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Quinidine helps control your condition but will not cure it. Continue to take quinidine even if you feel well. Do not stop taking quinidine without talking to your doctor.

Special Precautions

Before taking quinidine:

• tell your doctor and pharmacist if you are allergic to quinidine, quinine, or any other drugs.
• tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially anticoagulants ('blood thinners') such as warfarin (Coumadin); antidepressants; cimetidine (Tagamet); codeine products; diltiazem (Cardizem, Dilacor, Tiazac); medication for heart disease or high blood pressure; medications for seizures, sleep, or an infection; and vitamins.
• tell your doctor if you have an infection or have or have ever had myasthenia gravis; heart, kidney, or liver disease; or muscle weakness.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking quinidine, call your doctor.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking quinidine.
• you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how this drug affects you.
• remember that alcohol can add to the drowsiness caused by this drug.
• talk to your doctor about the use of cigarettes and caffeine-containing beverages. These products may increase the irritability of your heart and interfere with the action of quinidine.
• do not change brands of medication without talking to your doctor.

Special dietary instructions

Avoid drinking grapefruit juice while taking quinidine. Do not change the amount of salt in your diet without talking to your doctor.

What to do if you forget a dose

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Side Effects

Minor Side Effects

Quinidine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• diarrhea
• stomach pain and cramps
• dizziness or lightheadedness
• headache
• fatigue
• weakness
• rash
• vision changes
• difficulty sleeping
• tremor

Severe Side Effects

If you experience any of the following symptoms, call your doctor immediately:

• irregular heartbeat
• chest pain
• skin rash
• hearing changes (ringing or loss of hearing)
• vision changes (blurred or light sensitivity)
• unusual bleeding or bruising

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].

Storage conditions needed for this medication

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose

In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

Other information

Keep all appointments with your doctor and the laboratory. Your doctor will need to determine your response to quinidine.

Take quinidine at the same time each day in regularly spaced intervals. Changing the time of your doses prevents quinidine from working effectively.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Brand names

• Cardioquin®
• Quinaglute Dura-Tabs®
• Quinidex Extentabs®
• Quinora®