QUINIDINE (Systemic)

Some commonly used brand names are:

In the U.S.?

• Cardioquin
• Quinaglute Dura-tabs
• Quinidex Extentabs
• Quin-Release

In Canada?

• Apo-Quinidine
• Biquin Durules
• Cardioquin
• Novoquinidin
• Quinaglute Dura-tabs
• Quinate
• Quinidex Extentabs

Generic name product may be available in the U.S. and Canada.

Category

• Antiarrhythmic
• antimalarial

Description

Quinidine (KWIN-i-deen)is used to treat abnormal heart rhythms. It is also used to treat malaria.

Do not confuse this medicine with quinine,which, although related, has different medical uses.

Quinidine is available only with your doctor's prescription, in the followingdosage forms:

Oral
• Tablets (U.S. and Canada)
• Extended-release tablets (U.S. and Canada)

Parenteral
• Injection (U.S. and Canada)

Before Using This Medicine

In deciding to use a medicine,the risks of taking the medicine must be weighed against the good it willdo. This is a decision you and your doctor will make. For quinidine, the followingshould be considered:

Allergies?Tell your doctor if you have ever had any unusual orallergic reaction to quinidine or quinine. Also tell your health care professionalif you are allergic to any other substances, such as foods, preservatives,or dyes.

Pregnancy?Studies on effects in pregnancy have not been donein either humans or animals. However, quinidine has been used during pregnancyand, although serious side effects are uncommon, it has been shown to causemild uterine contractions, premature labor, and blood problems in the neonate.

Breast-feeding?Quinidine passes into breast milk and, becauseof the potential for problems in the nursing infant, it is generally not recommendedin mothers who are breast-feeding.

Children?Quinidine has not been widely studied in children;however, it is used in children to treat abnormal heart rhythms and to treatmalaria. Children may be able to take higher doses than adults and may havefewer side effects (such as vomiting, loss of appetite, and diarrhea) thanadults.

Older adults?Many medicines have not been studied specificallyin older people. Therefore, it may not be known whether they work exactlythe same way they do in younger adults. Although there is no specific informationcomparing use of quinidine in the elderly with use in other age groups, thismedicine is not expected to cause different side effects or problems in olderpeople than it does in younger adults. However, quinidine may remain in thebodies of older adults longer than it does in younger adults, which may increasethe risk of side effects and which may require lower doses.

Other medicines?Although certain medicines should not be usedtogether at all, in other cases two different medicines may be used togethereven if an interaction might occur. In these cases, your doctor may want tochange the dose, or other precautions may be necessary. When you are takingquinidine, it is especially important that your health care professional knowif you are taking any of the following:

• Amiodarone?Effects may be increased because levels of quinidinein the body may be increased

• Digitalis medicines (heart medicine)?Effects may be increasedbecause levels of digitalis in the body may be increased

• Antidepressants, tricyclic, such as amitriptyline (e.g., Elavil),clomipramine (e.g., Anafranil), desipramine (e.g., Norpramin), doxepin (e.g.,Sinequan), imipramine (e.g., Tofranil), and nortriptyline (e.g., Pamelor)or
• Astemizole (e.g., Hismanal) or
• Chloroquine (e.g., Aralen) or
• Clarithromycin (e.g., Biaxin) or
• Cisapride (e.g., Propulsid) or
• Diphenhydramine (e.g., Benadryl) or
• Erythromycin (e.g., Erythrocin, Erytab) or
• Fludrocortisone (e.g., Florinef) or
• Halofantrine (e.g., Halfan) or
• Haloperidol (e.g., Haldol) or
• Indapamide (e.g., Lozol) or
• Maprotiline (e.g., Ludiomil) or
• Mefloquine (e.g., Lariam) or
• Other heart medicine, including bepridil (e.g., Vascor), beta-adrenergicblocking agents such as propranolol (e.g., Inderal), diltiazem (e.g., Cardizem),disopyramide (e.g. Norpace), encainide (e.g., Encaid), flecainide (e.g., Tambocor),ibutilide (e.g., Corvert), lidocaine (e.g., Xylocaine), procainamide (e.g.,Procanbid), propafenone (e.g., Rythmol), sotalol (e.g., Betapace, Sotacor),tocainide (e.g., Tonocard), and verapamil (e.g., Calan, Isoptin) or
• Pentamidine (e.g., NebuPent, Pentam) or
• Phenothiazines (e.g., chlorpromazine [e.g., Thorazine], perphenazine[e.g., Trilafon], prochlorperazine [e.g., Compazine], thioridazine [e.g.,Mellaril]) or
• Pimozide (e.g., Orap) or
• Risperidone (e.g., Risperdal) or
• Sparfloxacin (e.g., Zagam) or
• Tamoxifen (e.g., Nolvadex) or
• Thiothixene (e.g., Navane) or
• Trimethoprim and sulfamethoxazole combination (e.g., Bactrim, Septra)?Effectson the heart may be increased

• Urinary alkalizers (medicine that makes the urine less acid, suchas acetazolamide [e.g., Diamox], dichlorphenamide [e.g., Daranide], methazolamide[e.g., Neptazane], and sodium bicarbonate [baking soda])?Effects maybe increased because levels of quinidine in the body may be increased

Other medical problems?The presence of other medicalproblems may affect the use of quinidine. Make sure you tell your doctor ifyou have any other medical problems, especially:

• Electrolyte disorders?Quinidine may worsen heart rhythm problems

• Heart disease or
• Myasthenia gravis?Quinidine may make these conditions worse

• Kidney disease or
• Liver disease?Effects may be increased because of slower removalof quinidine from the body

Proper Use of This Medicine

Take this medicine exactly as directed. Do not take more of this medicineand do not take it more often than your doctor ordered. Do not miss any doses.

Taking quinidine with food may help lessen stomach upset.

For patients taking the extended-release tabletform of this medicine:

• Quinidex Extentabs or Biquin Durules?Swallow the tablets whole;do not break, crush, or chew before swallowing. Note that Biquin Durules maysometimes appear as a whole tablet in the stool; this tablet is just the emptyshell that is left after the medicine has been absorbed into the body.
• Quinaglute Duratabs or Quin-Release?These tablets may be brokenin half; however, they should not be crushed or chewed before swallowing.

Dosing?The dose of quinidine will be different fordifferent patients. Follow your doctor's orders or thedirections on the label. The following information includes only theaverage doses of quinidine. If your dose is different,do not change it unless your doctor tells you to do so.

The number of tablets that you take depends on the strength of the medicine.Also, the number of doses you take each day, the timeallowed between doses, and the length of time you take the medicine dependon the medical problem for which you are taking quinidine.

• For regular (short-acting) oral dosageform (tablets):
  • For abnormal heart rhythm:
    • Adults?200 to 650 milligrams (mg) three or four times a day.
    • Children?30 to 40 mg per kilogram (kg) (13.6 to 18.2 mg perpound) of body weight per day. Your doctor may increase the dose if needed.
• For long-acting oral dosage form (tablets):
  • For abnormal heart rhythm:
    • Adults?300 to 660 mg every eight to twelve hours.
    • Children?30 to 40 mg per kilogram (kg) (13.6 to 18.2 mg perpound) of body weight per day. Your doctor may increase the dose if needed.
• For injection dosage form:
  • For abnormal heart rhythm:
    • Adults?190 to 380 mg injected into the muscle every two tofour hours. Or, up to 0.25 mg per kg (0.11 mg per pound) of body weight perminute in a solution injected into a vein.
    • Children?Dose must be determined by your doctor.
  • For malaria:
    • Adults?10 mg per kg (4.54 mg per pound) of body weight in asolution injected slowly into a vein over one to two hours. Then, 0.02 mgper kg (0.009 mg per pound) of body weight per minute is given. Or, 24 mgper kg (10.91 mg per pound) of body weight in a solution injected slowly intoa vein over a four-hour period. Then, eight hours after the first dose, 12mg per kg (5.45 mg per pound) of body weight, injected slowly into a veinover a four-hour period, and repeated every eight hours.
    • Children?Dose must be determined by your doctor.

Missed dose?If you miss a dose of this medicine and rememberwithin 2 hours of the missed dose, take it as soon as possible. However, ifyou do not remember until later, skip the missed dose and go back to yourregular dosing schedule. Do not double doses.

Storage?To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in otherdamp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be surethat any discarded medicine is out of the reach of children.

Precautions While Using This Medicine

It isvery important that your doctor check your progress at regular visits to makesure that the quinidine is working properly and does not cause unwanted effects.

Do not stop taking this medicine without first checking with your doctor,to avoid possible worsening of your condition.

Before having any kind of surgery (including dental surgery) or emergencytreatment, tell the medical doctor or dentist in charge that you are takingthis medicine.

Dizziness or lightheadedness may occur with this medicine, especially whenyou get up from a lying or sitting position. Getting up slowly may help.

Fainting may occur with this medicine. Do not drive or do anything else that could be dangerous iffainting occurs.

. Check with your doctor immediately if you faintor experience other side effects with this medicine.

Your doctor may want you to carry a medical identification card or braceletstating that you are using this medicine.

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects.Although not all of these side effects may occur, if they do occur they mayneed medical attention.

Check with your doctor immediately if any ofthe following side effects occur:

Less common

Abdominal pain and/or yellow eyes or skin; blurred and/or double vision, confusion, delirium, disturbed color perception,headache, noises or ringing in the ear, and/or visual intolerance of light; dizziness or lightheadedness; fainting; fever

Rare

Chest pain, fever, general discomfort, joint pain, joint swelling,muscle pain, and/or skin rash; nosebleeds or bleedinggums; unusual tiredness or weakness and/or pale skin

Other side effects may occur that usually do not need medical attention.These side effects may go away during treatment as your body adjusts to themedicine. However, check with your doctor if any of the following side effectscontinue or are bothersome:

More common

Diarrhea; loss of appetite; muscle weakness; nausea or vomiting

Other side effects notlisted above may also occur in some patients. If you notice any other effects,check with your doctor.