Quinidine, Oral

What are other names for this medicine?

Type of medicine: antiarrhythmic (treats irregular heartbeats)

Generic and brand names: quinidine gluconate, oral; quinidine sulfate, oral; quinidine, oral

What is this medicine used for?

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

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have ever had:

• an allergic reaction to any medicine
• a bleeding disorder
• heart disease
• kidney problems
• liver problems
• myasthenia gravis
• problems with low potassium levels in your blood.

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

How do I take it?

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

Take this medicine 1 hour before or 2 hours after meals. If this medicine upsets your stomach, 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 healthcare provider.

What should I watch out for?

Your healthcare 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 healthcare 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.

Talk with your healthcare provider before changing your diet or taking any supplements. Salt and potassium may affect the way this medicine works. Follow your healthcare provider's instructions carefully.

This medicine may make your skin more sensitive to the sun, which may lead to painful sunburns. while you are taking this medicine, avoid long exposure to the sun. wear protective clothing, a hat and sunscreen lotion with an SFP of at least 30 when you need to be outdoors. Do not use a sunlamp. If you get a severe sunburn, contact your healthcare provider right away.

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

If you need emergency care, surgery, or dental work, tell the healthcare provider or dentist you are taking this medicine.

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 healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away. If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives; itching; rash; trouble breathing; tightness in your chest; swelling of your lips, tongue, and throat), irregular or rapid heartbeat.

Serious (report these to your healthcare provider right away): Unusual bruising or bleeding, fever, ringing in your ears, hearing loss, blurred vision, delirium, depression, yellow eyes or skin, severe stomach pain, severe dizziness or fainting, muscle or joint pain.

Other: Headache, weakness, nausea, dizziness, diarrhea, vomiting, change in sense of taste.

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 healthcare provider if you are taking:

• amiloride (Midamor)
• amphetamines such as methylphenidate (Ritalin) and dextroamphetamine (Dexedrine)
• antacids (take them 2 hours apart from doses of this medicine)
• antibiotics such as clarithromycin (Biaxin), erythromycin (Erythrocin, EES, Ery-Tab, EryPed), and moxifloxacin (Avelox)
• antidepressants such as amitriptyline, imipramine (Tofranil), nortriptyline (Aventyl, Pamelor), and doxepin (Sinequan)
• antifungals such as itraconazole (Sporanox) and ketoconazole (Nizoral)
• antiseizure medicines such as carbamazepine (Tegretol), phenytoin (Dilantin), and primidone (Mysoline)
• barbiturates such as phenobarbital, butabarbital (Butisol), and pentobarbital (Nembutal)
• beta blockers such as atenolol (Tenormin), acebutolol (Sectral), pindolol, metoprolol (Lopressor, Toprol XL), sotalol (Betapace), nadolol (Corgard), propranolol (Inderal), labetalol (Normodyne, Trandate), and carvedilol (Coreg)
• cimetidine (Tagamet)
• cyclosporine (Sandimmune, Neoral)
• dextromethorphan, an ingredient in many cough and cold medicines such as Robitussin-DM
• ephedra
• heart medicines such as digoxin (Lanoxin), disopyramide (Norpace), procainamide (Pronestyl, Procanbid), amiodarone (Pacerone, Cordarone), diltiazem (Cardizem, Cartia, Dilacor, Tiamate, Tiazac), and verapamil (Calan, Isoptin, Verelan)
• medicines to treat HIV such as amprenavir (Agenerase), indinavir (Crixivan), nelfinavir (Viracept), nevirapine (Viramune), delavirdine (Rescriptor), ritonavir (Norvir), and saquinavir (Fortovase, Invirase)
• phenothiazines such as chlorpromazine (Thorazine), prochlorperazine (Compazine), perphenazine, promazine (Sparine), thioridazine, and trifluoperazine (Stelazine)
• rifampin (Rifadin, Rimactane)
• St. John's wort
• warfarin (Coumadin).

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

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

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

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare 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.