Quinidine, Oral

What are other names for this medicine?

Generic and brand names: quinidine gluconate, oral; quinidine polygalacturonate, oral; quinidine sulfate, oral; quinidine, oral; Cardioquin; Quinaglute Dura-Tabs; Quinalan; Quinidex Extentabs; Quinora

What is this medicine used for?

This medicine is taken by mouth to treat several kinds of arrhythmias (irregular heartbeats). Your health care provider will explain why you are taking this medicine.

How do I take it?

Take this medicine exactly as your health care provider prescribes. Take it regularly, even if you begin to feel better. Do not stop taking this medicine until your health care provider tells you to.

Take this medicine 1 hour before or 2 hours after meals. If this medicine upsets your stomach, ask your health care provider if you can take it with milk or a snack. If you are taking extended-release tablets, swallow them whole. Do not open, crush, or chew them.

If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your health care provider.

What should I watch out for?

Your health care provider will want to see you regularly to check your heart. If you notice an irregular or rapid heartbeat or if you faint, contact your health care provider right away.

You will need to have blood tests to find out how this medicine is affecting you. Keep all your appointments for blood tests.

Your health care provider may want to check the level of potassium in your blood. You need to have a normal potassium level for this medicine to work properly. Follow your health care provider's instructions if you need to raise or lower your blood potassium level.

This medicine may make you dizzy or lightheaded. Do not drive or operate machinery unless you are fully alert.

Females of childbearing age: Tell your health care provider if you are pregnant or plan to become pregnant. Do not breast-feed while taking this medicine without your health care provider's approval.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your health care provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your health care provider right away. If you are unable to reach your health care provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives, itching, rash, tightness in your chest, trouble breathing).

Serious (report these to your health care provider right away): Irregular or rapid heartbeat, fainting, delirium, depression.

Other: Headache, fever, rash, asthma, muscle or joint pain, blurred vision, ringing in your ears, hearing loss, nausea, dizziness, lightheadedness.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your health care provider if you are taking:

• antacids (take them 2 hours apart from doses of this medicine)
• amiodarone (Cordarone)
• blood thinners such as warfarin (Coumadin)
• cimetidine (Tagamet)
• digoxin (Lanoxin) and digitoxin (Crystodigin)
• disopyramide (Norpace)
• procainamide (Pronestyl, Procanbid)
• rifampin (Rifadin, Rimactane)
• verapamil (Calan, Isoptin, Verelan).

Many more drugs may interact with this medicine. Be sure that you tell your health care provider about all other medicines you are taking, especially those prescribed by other health care providers.

The effects of this medicine may be increased if you take it with grapefruit juice. Discuss this with your health care provider.

Keep a list of all your medicines (prescription, nonprescription, supplements, natural remedies, and vitamins) with you. Be sure that you tell all health care providers who treat you about all the products you are taking.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your health care provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.