Quinine Sulfate

QUININE SULFATE- quinine sulfate capsule
Amneal Pharmaceuticals LLC


Quinine sulfate use for the treatment or prevention of nocturnal leg cramps may result in serious and life-threatening hematologic reactions, including thrombocytopenia and hemolytic uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP). Chronic renal impairment associated with the development of TTP has been reported. The risk associated with quinine sulfate use in the absence of evidence of its effectiveness in the treatment or prevention of nocturnal leg cramps outweighs any potential benefit [see Indications and Usage (1) and Warnings and Precautions (5.1)].


Quinine sulfate is an antimalarial drug indicated only for treatment of uncomplicated Plasmodium falciparum malaria. Quinine sulfate has been shown to be effective in geographical regions where resistance to chloroquine has been documented [see Clinical Studies (14)].

Limitations of Use:

Quinine sulfate capsules are not approved for:

  • Treatment of severe or complicated P. falciparum malaria.
  • Prevention of malaria.
  • Treatment or prevention of nocturnal leg cramps [see Warnings and Precautions (5.1)].


2.1 Treatment of Uncomplicated P. falciparum Malaria

For treatment of uncomplicated P. falciparum malaria in adults: Orally, 648 mg (two capsules) every 8 hours for 7 days [see Clinical Studies (14)].

Quinine sulfate capsules should be taken with food to minimize gastric upset [see Clinical Pharmacology (12.3)].

2.2 Renal Impairment

In patients with acute uncomplicated malaria and severe chronic renal impairment, the following dosage regimen is recommended: one loading dose of 648 mg quinine sulfate followed 12 hours later by maintenance doses of 324 mg every 12 hours. The effects of mild and moderate renal impairment on the safety and pharmacokinetics of quinine sulfate are not known [see Use in Specific Populations (8.6) and Clinical Pharmacology (12.3)].

2.3 Hepatic Impairment

Adjustment of the recommended dose is not required in mild (Child-Pugh A) or moderate (Child-Pugh B) hepatic impairment, but patients should be monitored closely for adverse effects of quinine. Quinine should not be administered in patients with severe (Child-Pugh C) hepatic impairment [see Use in Specific Populations (8.7) and Clinical Pharmacology (12.3)].


Quinine Sulfate Capsules USP, 324 mg are supplied as clear transparent size ‘0’ hard gelatin capsule filled with white to off-white powder and imprinting ‘AMNEAL’ on the cap and ‘811’ on the body.


Quinine sulfate capsules are contraindicated in patients with the following:

  • Prolonged QT interval. One case of a fatal ventricular arrhythmia was reported in an elderly patient with a prolonged QT interval at baseline, who received quinine sulfate intravenously for P. falciparum malaria [see Warnings and Precautions (5.4)].
  • Known hypersensitivity reactions to quinine. These include, but are not limited to, the following [see Warnings and Precautions (5.7)]:
    • Thrombocytopenia
    • Idiopathic thrombocytopenia purpura (ITP) and thrombotic thrombocytopenic purpura (TTP)
    • Hemolytic uremic syndrome (HUS)
    • Blackwater fever (acute intravascular hemolysis, hemoglobinuria, and hemoglobinemia)
  • Known hypersensitivity to mefloquine or quinidine: cross-sensitivity to quinine has been documented [see Warnings and Precautions (5.7)].
  • Myasthenia gravis. Quinine has neuromuscular blocking activity, and may exacerbate muscle weakness.
  • Optic neuritis. Quinine may exacerbate active optic neuritis [see Adverse Reactions (6.1)].


5.1 Use of Quinine Sulfate for Treatment or Prevention of Nocturnal Leg Cramps

Quinine sulfate may cause unpredictable serious and life-threatening hematologic reactions including thrombocytopenia and hemolytic-uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP) in addition to hypersensitivity reactions, QT prolongation, serious cardiac arrhythmias including torsades de pointes, and other serious adverse events requiring medical intervention and hospitalization. Chronic renal impairment associated with the development of TTP, and fatalities have also been reported. The risk associated with the use of quinine sulfate in the absence of evidence of its effectiveness for treatment or prevention of nocturnal leg cramps, outweighs any potential benefit in treating and/or preventing this benign, self-limiting condition [see Boxed Warning and Contraindications (4)].

5.2 Thrombocytopenia

Quinine-induced thrombocytopenia is an immune-mediated disorder. Severe cases of thrombocytopenia that are fatal or life threatening have been reported, including cases of HUS/TTP. Chronic renal impairment associated with the development of TTP has also been reported. Thrombocytopenia usually resolves within a week upon discontinuation of quinine. If quinine is not stopped, a patient is at risk for fatal hemorrhage. Upon re-exposure to quinine from any source, a patient with quinine-dependent antibodies could develop thrombocytopenia that is more rapid in onset and more severe than the original episode.

5.3 Hemolytic Anemia

Acute hemolytic anemia has been reported in patients receiving quinine for treatment of malaria, including patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. The cause for the acute hemolytic anemia in quinine-treated patients with malaria and its potential relationship with G6PD deficiency has not been determined. Closely monitor hemoglobin and hematocrit during quinine treatment. Quinine should be discontinued if patients develop acute hemolytic anemia.

5.4 QT Prolongation and Ventricular Arrhythmias

QT interval prolongation has been a consistent finding in studies which evaluated electrocardiographic changes with oral or parenteral quinine administration, regardless of age, clinical status, or severity of disease. The maximum increase in QT interval has been shown to correspond with peak quinine plasma concentration [see Clinical Pharmacology (12.2)]. Quinine sulfate has been rarely associated with potentially fatal cardiac arrhythmias, including torsades de pointes, and ventricular fibrillation.

Quinine sulfate has been shown to cause concentration-dependent prolongation of the PR and QRS interval. At particular risk are patients with underlying structural heart disease and preexisting conduction system abnormalities, elderly patients with sick sinus syndrome, patients with atrial fibrillation with slow ventricular response, patients with myocardial ischemia or patients receiving drugs known to prolong the PR interval (e.g., verapamil) or QRS interval (e.g., flecainide or quinidine) [see Clinical Pharmacology (12.2)].

Quinine sulfate is not recommended for use with other drugs known to cause QT prolongation, including Class IA antiarrhythmic agents (e.g., quinidine, procainamide, disopyramide), and Class III antiarrhythmic agents (e.g., amiodarone, sotalol, dofetilide).

The use of macrolide antibiotics such as erythromycin should be avoided in patients receiving quinine sulfate. Fatal torsades de pointes was reported in an elderly patient who received concomitant quinine, erythromycin, and dopamine.

Although a causal relationship between a specific drug and the arrhythmia was not established in this case, erythromycin is a CYP3A4 inhibitor and has been shown to increase quinine plasma levels when used concomitantly. A related macrolide antibiotic, troleandomycin, has also been shown to increase quinine exposure in a pharmacokinetic study [see Drug Interactions (7)].

Quinine may inhibit the metabolism of certain drugs that are CYP3A4 substrates and are known to cause QT prolongation, e.g., astemizole, cisapride, terfenadine, pimozide, halofantrine and quinidine. Torsades de pointes has been reported in patients who received concomitant quinine and astemizole.

Therefore, concurrent use of quinine sulfate with these medications, or drugs with similar properties, should be avoided [see Drug Interactions (7)].

Concomitant administration of quinine sulfate with the antimalarial drugs, mefloquine or halofantrine, may result in electrocardiographic abnormalities, including QT prolongation, and increase the risk for torsades de pointes or other serious ventricular arrhythmias.

Concurrent use of quinine sulfate and mefloquine may also increase the risk of seizures [see Drug Interactions (7)].

Quinine sulfate should also be avoided in patients with known prolongation of QT interval and in patients with clinical conditions known to prolong the QT interval, such as uncorrected hypokalemia, bradycardia, and certain cardiac conditions [see Contraindications (4)].

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