Quinidine Sulfate

  • CHF and arrhythmias

Quinidine Sulfate Generic Name & Formulations

General Description

Quinidine sulfate 300mg; ext-rel tabs.

Pharmacological Class

Class I antiarrhythmic.

How Supplied

Contact supplier.

Quinidine Sulfate Indications


Atrial and ventricular arrhythmias (see full labeling).

Quinidine Sulfate Dosage and Administration


Take with food and in an upright position. 300–600mg every 8–12hrs.


Not recommended.

Quinidine Sulfate Contraindications


Complete AV or bundle branch block or other severe intraventricular conduction defects. Myasthenia gravis. Arrhythmias due to digitalis intoxication. Aberrant impulses, abnormal rhythms due to escape mechanisms.

Quinidine Sulfate Boxed Warnings

Not Applicable

Quinidine Sulfate Warnings/Precautions


Atrial flutter; digitalize first. Incomplete AV block. Marginally compensated cardiovascular disease. Heart failure. Hypotension. Renal or hepatic dysfunction. Monitor blood, liver and kidney function in long-term use. Monitor ECG and serum levels if dose is over 2.5g/day. Pregnancy (Cat.C). Nursing mothers.

Quinidine Sulfate Pharmacokinetics

See Literature

Quinidine Sulfate Interactions


Toxicity increased by amiodarone, cimetidine, ranitidine, diuretics, carbonic anhydrase inhibitors, sodium bicarbonate, verapamil, diltiazem. Potentiates anticoagulants, anticholinergics, neuromuscular blocking agents, phenothiazines, reserpine, timolol. Increases digitalis serum levels. Plasma levels decreased by barbiturates, hydantoins, rifampin, nifedipine.

Quinidine Sulfate Adverse Reactions

Adverse Reactions

Nausea, vomiting, abdominal pain, diarrhea, new or exacerbated arrhythmias, heart block, syncope, cinchonism, headache, blood dyscrasias, hypotension, flushing, impaired hearing and vision, allergic reactions, hepatic dysfunction.

Quinidine Sulfate Clinical Trials

See Literature

Quinidine Sulfate Note


Formerly known under the brand names Cin-quin, Quinidex, Quinora.

Quinidine Sulfate Patient Counseling

See Literature