Quinine

Quinine sulfate capsule USP is a cinchona alkaloid indicated for treatment of uncomplicated Plasmodium falciparum malaria. Quinine sulfate capsule USP 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. Quinine sulfate capsules USP are not approved for: Treatment of severe or complicated P. falciparum malaria. Prevention of malaria. Treatment or prevention of nocturnal leg cramps.

Quinine is an antimalarial agent.

Adults (≥ 16 years of age): 648 mg (two capsules) every 8 hours for 7 days. Patients with severe chronic renal impairment: one loading dose of 648 mg (two capsules) followed 12 hours later by 324 mg (one capsule) every 12 hours for 7 days.

Quinine sulfate is contraindicated in patients with the following: Prolongation of QT interval. Glucose-6-phosphate dehydrogenase (G6PD) deficiency. Myasthenia gravis. Known hypersensitivity to quinine, mefloquine, or quinidine. Optic neuritis. Quinine sulfate is 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. • Glucose-6-phosphate dehydrogenase (G6PD) deficiency. • Hemolysis can occur in patients with G6PD deficiency receiving quinine.

Boxed warning (hematologic reactions): Quinine sulfate capsules 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. Not indicated for the prevention or treatment of nocturnal leg cramps. Risk of serious and life-threatening adverse reactions. Thrombocytopenia, including ITP and HUS/TTP, has been reported. Discontinue drug. QT prolongation and ventricular arrhythmias. Avoid concomitant use with drugs known to prolong QT interval. Avoid concomitant use with rifampin. Quinine sulfate treatment failures have been reported. Avoid concomitant use with neuromuscular blocking agents.

Most common adverse reactions are a cluster of symptoms called "cinchonism", which occurs to some degree in almost all patients taking quinine: headache, vasodilation and sweating, nausea, tinnitus, hearing impairment, vertigo or dizziness, blurred vision, disturbance in color perception, vomiting, diarrhea, abdominal pain, deafness, blindness, and disturbances in cardiac rhythm or conduction.

Interacting Drug Interaction Drugs known to prolong QT interval (e.g., Class IA and Class III antiarrhythmic agents). Quinine sulfate prolongs QT interval, ECG abnormalities including QT prolongation and Torsades de Pointes. Avoid concomitant use. Other antimalarials (e.g., halofantrine, mefloquine). ECG abnormalities including QT prolongation Avoid concomitant use. CYP3A4 inducers or inhibitors Alteration in plasma quinine concentration. Monitor for lack of efficacy or increased adverse events of quinine. CYP3A4 and CYP2D6 substrates Quinine is an inhibitor of CYP3A4 and CYP2D6. Monitor for lack of efficacy or increased adverse events of the co-administered drug. Digoxin Increased digoxin plasma concentration. See full prescribing information for a complete list of reported and potential interactions.

Storage Store at 25°C (77°F), excursions permitted to 15° to 30°C (59° to 86°F).