Quinidine
Purpose of Medication and Method of Action
Quinidine is used for the treatment of abnormal heart rhythms (arrhythnias). The two arrhythmias for which quinidine is most commonly used are: the conversion of atrial fibrillation and maintenamce of normal sinus rhythm in successfully converted patients and the suppression of irregular beats of the ventricle.
Side Effects
The most common side effect is diarrhea which occurs in 20-25% of patients. Other less frequent side efects are: fever (6%), rash (6%), and dizziness (3%).
Drug Interactions
Drugs which will increase the blood levels of quinidine include diltiazem, acetazolamide, thiazide diuretics (HCTZ and furosemide), amiodarone, cimetadine, nifedipine, and verapamil. Quinidine can also affect the blood levels of other drugs the most important being the anticoagulant warfarin (Coumadin) and digoxin.
Cautions and Contraindications
Quinidine should be used with extreme caution in those with a history of heart block.
Usual Dose
One (324 mg)-two tablets every 6-12 hours - dose must be individualized. The tablets should not be crushed.
Patient Medication Information
These information sheets do not list all known side effects of the medications, only the most common side effects. For a complete list of side effects please contact your local pharmacy or the actual drug manufacturing company.