quinidine (cont.)
Quinidine increases the action of the blood thinner warfarin (Coumadin), due
to synergistic effects and can lead to excessive blood thinning and bleeding. A
decrease in warfarin dose usually is required. Blood levels of digoxin
(Lanoxin) are
raised by quinidine due to a reduction in removal or reduced distribution in the
body of digoxin. This can give rise to intoxication with digoxin, and it is
important to reduce the dose of digoxin to prevent toxicity.
Removal of quinidine by the liver is accelerated by phenobarbital,
phenytoin
(Dilantin), and rifampin (Rifamate), requiring an increase in quinidine dose.
With the exact mechanism not known, amiodarone (Cordarone), another type of
antiarrhythmic drug, may decrease removal of quinidine by the kidneys or liver
giving rise to elevated quinidine blood levels, which may result in
life-threatening arrhythmias, including torsades de pointes. It is important,
therefore, to decrease quinidine doses when it is given concomitantly with
amiodarone.
Cimetidine (Tagamet) increases quinidine levels by decreasing the elimination
of quinidine giving rise to elevated quinidine serum levels that may lead to
quinidine toxicity.
PREGNANCY: Safety and efficacy of quinidine has not been established in
pregnant women.
NURSING MOTHERS: Quinidine can enter
breast milk and should be avoided by
nursing mothers.
SIDE EFFECTS: The most common side effects are vomiting,
heartburn, rash,
fever, dizziness, fatigue, weakness and headache. If patients experience
irregular heartbeat, chest pain,
skin rash, hearing changes (ringing or
loss of
hearing), vision changes (blurred or light sensitivity) or unusual bleeding or
bruising they should call their doctor immediately.
Reference: FDA Prescribing Information
Last Editorial Review: 7/31/2009
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
- Drug Interactions - Learn about potential drug interactions you may be exposed to. Drug interactions can occur with prescription drugs, OTC medication, vitamins, herbs, and supplements.
- Liver Blood Tests - Learn about liver blood tests used to detect liver damage disease such as fatty liver, cirrhosis, hepatitis, Tylenol liver damage, and more. This includes measuring the aminotransferases enzymes (AST and ALT levels)
- Lupus - Get information on lupus (SLE) disease treatment, signs, diagnosis, types of symptoms (butterfly, discoid rash), causes, pregnancy flares, prevention and statistics.
Latest Medical News
Back to Medications Index
Heart RSS