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ANTIPARASITIC PRODUCTS, INSECTICIDES AND REPELLENTS › ANTIPROTOZOALS › ANTIMALARIALS › Aminoquinolines
chloroquine
P01BA01
Forms & Strengths
- Oral tablets: 250 mg and 500 mg chloroquine phosphate (equivalent to 150 mg and 300 mg base)
Adult Dosing
- Malaria prophylaxis: 500 mg base (600 mg salt) orally once weekly, starting 2 weeks prior to exposure and continuing for 4 weeks after leaving endemic area
- Malaria treatment (uncomplicated): 1 g base (1.2 g salt) initially, followed by 500 mg base at 6, 24, and 48 hours
- Extraintestinal amebiasis: 1 g base daily for 2 days, then 500 mg daily for at least 2 to 3 weeks
Pediatric Dosing
- Malaria prophylaxis: 5 mg base/kg (not to exceed 500 mg base) orally once weekly
- Malaria treatment (uncomplicated): 10 mg base/kg initially (max 600 mg base), then 5 mg/kg at 6, 24, and 48 hours
Indications
- Treatment and prophylaxis of malaria caused by susceptible strains of Plasmodium vivax, P. malariae, P. ovale, and P. falciparum
- Treatment of extraintestinal amebiasis
Mechanism of Action
- Concentrates in the acidic food vacuoles of intraerythrocytic parasites, inhibiting the enzyme heme polymerase
- Prevents the polymerization of toxic free heme into nontoxic hemozoin, leading to parasite lysis and death
Contraindications
- Hypersensitivity to chloroquine or 4-aminoquinoline derivatives
- Presence of retinal or visual field changes attributable to any 4-aminoquinoline compound
- Long-term use in children (associated with severe toxicity)
Adverse Reactions
- Common: nausea, vomiting, diarrhea, abdominal cramps, headache, dizziness, pruritus
- Serious: irreversible retinopathy, cardiomyopathy, QT prolongation, severe hypoglycemia, neuropsychiatric effects, myopathy, agranulocytosis
Drug Interactions
- Antacids and kaolin decrease absorption of chloroquine
- Increases plasma concentrations and toxicity of digoxin and cyclosporine
- Co-administration with QT-prolonging drugs (e.g., amiodarone, macrolides, antipsychotics) increases risk of ventricular arrhythmias
- May reduce the antibody response to intradermal human diploid cell rabies vaccine
Curated Content: Needs Vetting Before Put to Clinical Use