In many antiarrhythmic drug trials for non-life-threatening arrhythmias, active antiarrhythmic drug therapy was associated with increased mortality.
Risk associated with antiarrhythmic drug therapy probably is greatest in patients with structural heart disease.
A meta-analysis of data from several randomized, controlled studies in patients with atrial flutter and fibrillation indicates that quinidine therapy may be associated with a mortality rate >3 times higher than that associated with placebo.
A meta-analysis in patients with various non-life-threatening ventricular arrhythmias showed mortality associated with quinidine was consistently greater than that associated with various other antiarrhythmic agents (i.e., flecainide, mexiletine, propafenone, tocainide).
Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. The tablets may be broken in half, but should not be crushed or chewed. Take your doses at regular intervals. Do not take your medicine more often than directed. Do not stop taking this medicine suddenly. This may cause serious, heart-related side effects. Your doctor will tell you how much medicine to take. If your doctor wants you to stop the medicine, the dose will be slowly lowered over time to avoid any side effects.
Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.
Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
What may interact with this medicine?
Do not take this medicine with any of the following medications:
This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.
What should I watch for while using this medicine?
Visit your doctor or health care professional for regular checks on your progress. Wear a medical ID bracelet or chain, and carry a card that describes your disease and details of your medicine and dosage times.
Check your blood pressure and pulse rate regularly. Ask your health care professional what your blood pressure and pulse rate should be, and when you should contact him or her. Your doctor or health care professional also may schedule regular blood tests and electrocardiograms to check your progress.
You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.
This medicine can make you more sensitive to the sun. Keep out of the sun. If you cannot avoid being in the sun, wear protective clothing and use sunscreen. Do not use sun lamps or tanning beds/booths.
What side effects may I notice from receiving this medicine?
Side effects that you should report to your doctor or health care professional as soon as possible:
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
diarrhea
flushing of the skin with intense itching
heartburn
loss of appetite
stomach pain
This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Where should I keep my medicine?
Keep out of the reach of children.
Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Protect from light. Keep container tightly closed. Throw away any unused medicine after the expiration date.
NOTE:This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.
Remember, keep this and all other medicines out of the reach of children,
never share your medicines with others, and use this medication only for the indication prescribed.