quinidine gluconate
quinidine polygalacturonate
quinidine sulfate
Pregnancy Risk Category C
How supplied
quinidine bisulfate
Tablets (extended-release): 250 mg†‡
quinidine gluconate
Tablets (extended-release): 324 mg, 325 mg†, 330 mg
Injection: 80 mg/ml
quinidine polygalacturonate
Tablets: 275 mg
quinidine sulfate
Tablets: 200 mg, 300 mg
Tablets (extended-release): 300 mg
Capsules: 200 mg, 300 mg
Injection: 200 mg/ml†
Action
A class IA antiarrhythmic that has both direct and indirect (anticholinergic) effects on cardiac tissue. Drug decreases automaticity, conduction velocity, and membrane responsiveness. The effective refractory period is prolonged, and the anticholinergic action reduces vagal tone.
Indications & dosage
Atrial flutter or fibrillation--
Adults: 300 to 400 mg quinidine sulfate or equivalent base P.O. q 6 hours. Or, 200 mg P.O. q 2 to 3 hours for 5 to 8 doses, increased daily until sinus rhythm is restored or toxic effects develop. Administer quinidine only after AV node has been blocked with a beta blocker, digoxin, or a calcium channel blocker to avoid increasing AV conduction. Maximum dose is 3 to 4 g daily.
Paroxysmal supraventricular tachycardia--
Adults: 400 to 600 mg P.O. gluconate q 2 to 3 hours until toxic adverse reactions develop or arrhythmia subsides.
Premature atrial and ventricular contractions, paroxysmal AV junctional rhythm, paroxysmal atrial tachycardia, paroxysmal ventricular tachycardia, maintenance after cardioversion of atrial fibrillation or flutter--
Adults: test dose is 200 mg P.O. or I.M. Quinidine sulfate or equivalent base 200 to 400 mg P.O. q 4 to 6 hours or 600 mg quinidine sulfate extended-release every 8 to 12 hours; or quinidine gluconate 800 mg (10 ml of commercially available solution) added to 40 ml of D5W, infused I.V. at 2.5 mg/kg/minute.
Children: 30 mg/kg/24 hours or 900 mg/
m2/24 hours P.O. in five divided doses.
Severe Plasmodium falciparum malaria--
Adults: 10 mg/kg gluconate I.V. diluted in 250 ml of normal saline solution and infused over 1 to 2 hours; then a continuous maintenance infusion of 0.02 mg/kg/
minute for 72 hours or until parasitemia is reduced to less than 1%.
Adjust-a-dose: Use reduced dosage for patients with impaired hepatic function or heart failure.
Adverse reactions
CNS: vertigo, headache, light-headedness, confusion, ataxia, depression, dementia.
CV: PVC; ventricular tachycardia; atypical ventricular tachycardia (torsades de pointes); hypotension; complete AV block, tachycardia; aggravated heart failure; ECG changes (particularly widening of QRS complex, widened QT and PR intervals).
EENT: tinnitus, excessive salivation, blurred vision, diplopia, photophobia.
GI: diarrhea, nausea, vomiting, anorexia, abdominal pain.
Hematologic: hemolytic anemia, thrombocytopenia, agranulocytosis.
Hepatic: hepatotoxicity.
Respiratory: acute asthmatic attack, respiratory arrest.
Skin: rash, petechial hemorrhage of buccal mucosa, pruritus, urticaria, lupus erythematosus, photosensitivity.
Other: angioedema, fever, cinchonism.
Interactions
Drug-drug. Acetazolamide, antacids, sodium bicarbonate, thiazide diuretics: may increase quinidine blood levels because of alkaline urine. Monitor for increased effect.
Amiodarone, cimetidine: increased serum quinidine levels. Monitor for increased effect.
Barbiturates, phenytoin, rifampin: may lower blood levels of quinidine. Monitor for decreased effect.
Digoxin: increased serum digoxin levels after initiating quinidine therapy. Monitor closely.
Fluvoxamine, nefazodone, tricyclic antidepressants: increased blood levels with increased effect. Monitor closely.
Nifedipine: may decrease quinidine blood levels. Monitor carefully.
Other antiarrhythmics (such as lidocaine, procainamide, propranolol): increased risk of toxicity. Use together cautiously.
Verapamil: may result in hypotension, bradycardia, or AV block. Monitor blood pressure and heart rate.
Warfarin: increased anticoagulant effect. Monitor closely.
Drug-herb. Jimsonweed: may adversely affect CV function. Avoid concomitant use.
Licorice: may prolong the QT interval and be additive. Use together cautiously.
Effects on diagnostic tests
None reported.
Contraindications
Contraindicated in patients with idiosyncrasy or hypersensitivity to quinidine or related cinchona derivatives and in those with myasthenia gravis, intraventricular conduction defects, digitalis toxicity when AV conduction is grossly impaired, abnormal rhythms due to escape mechanisms, and history of prolonged QT syndrome. Also contraindicated in patients who developed thrombocytopenia with prior exposure to quinidine or quinine.
Nursing considerations
I.V. administration
Patient teaching
*Liquid contains alcohol. **May contain tartrazine. †Canada ‡Australia §U.K. OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING