Chloroquine


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO Acute malaria As base: Initial: 600 mg, then 300 mg 6-8 hr later on day 1. Continue w/ 300 mg/day on days 2 and 3. Malaria prophylaxis As chloroquine base: 300 mg once weekly preferably same day each week, starting 1 week before exposure, continuing throughout only on a weekly basis and for at least 4 weeks after exposure. Discoid and SLE; Rheumatoid arthritis As base: Initial: 150 mg/day. Max: 2.5 mg/kg/day. Hepatic amoebiasis As base: W/ emetine or dehydroemetine: 600 mg/day for 2 days then 300 mg/day for 2-3 wk. I
Dosage Details
Oral
Acute malaria
Adult: As base: Initially, 600 mg followed by 300 mg 6-8 hr later on day 1. On days 2 and 3, single doses of 300 mg/day.
Child: Initially, 10 mg base/kg (max 600 mg base) followed by 5 mg base/kg (max 300 mg base) after 6 hrs. Single doses of 5 mg base/kg on days 2 and 3.

Oral
Hepatic amoebiasis
Adult: As base: 600 mg daily for 2 days then 300 mg daily for 2 or 3 wk given with emetine or dehydroemetine.
Child: 6 mg/kg daily. Max dose: 300 mg daily.

Oral
Rheumatoid arthritis
Adult: As base: 150 mg daily. Max: 2.5 mg/kg daily. Discontinue treatment if there is no improvement after 6 mth.
Child: Up to 3 mg/kg/day. Discontinue treatment if there is no improvement after 6 mth.

Oral
Discoid and systemic lupus erythematosus
Adult: As base: Initially, 150 mg once daily, reduce gradually after maximal response. Max dose: 2.5 mg/kg daily.
Child: 3 mg/kg daily.

Oral
Prophylaxis of malaria
Adult: As chloroquine base: 300 mg once weekly preferably same day each week, starting 1 week before exposure, continuing throughout only on a weekly basis and for at least 4 weeks after exposure.
Child: As chloroquine base: 5 mg/kg weekly, starting 1 week before exposure, continuing throughout only on a weekly basis and for at least 4 weeks after exposure.
Renal Impairment
May need to reduce dose in prolonged treatment.
Administration
Should be taken with food.
Contraindications
Hypersensitivity, known or suspected resistant P. falciparum infection, porphyria, retinal damage, concurrent hepatotoxic drugs.
Special Precautions
Psoriasis, diseases of the haematopoietic or CNS systems, myasthenia gravis, hepatic or renal impairment, G6PD deficiency, epilepsy, childn. Pregnancy and lactation. Slow infusion is used upon IV admin to prevent cardiotoxicity.
Adverse Reactions
Retinopathy, hair loss, photosensitivity, tinnitus, myopathy (long-term therapy). Psychosis, seizures, leucopenia and rarely aplastic anaemia, hepatitis, GI upsets, dizziness, hypokalaemia, headache, pruritus, urticaria, difficulty in visual accommodation.
Potentially Fatal: Cardiac and respiratory arrest, CV collapse, convulsions, coma.
Overdosage
Symptoms include headache, drowsiness, visual disturbances, nausea and vomiting, CV collapse, shock and convulsions followed by sudden and early respiratory and cardiac arrest. ECG may reveal atrial standstill, nodal rhythm, prolonged intraventricular conduction time and progressive bradycardia leading to ventricular fibrillation and/or arrest. Treatment is symptomatic and should be prompt with immediate evacuation of the stomach by emesis or gastric lavage. Finely powdered, activated charcoal may be used within 30 min after ingestion of the antimalarial to reduce intestinal absorption of the drug. To be effective, the dose of activated charcoal should be at least five times the estimated dose of chloroquine ingested.
Drug Interactions
Concomitant therapy with phenylbutazone predisposes to dermatitis, antagonises effect of neostigmine and pyridostigmine, reduces bioavailability of ampicillin. Cimetidine inhibits metabolism of chloroquine raising plasma levels.
Potentially Fatal: Increased risks of inducing ventricular arrhythmias with halofantrine or other arrhythmogenic drugs eg, amiodarone. Increased risk of convulsions with mefloquine. Antacids reduce absorption of chloroquine hence admin should be separated by 4 hrs. Rarely Stevens-Johnson syndrome, when administered with pyrimethamine/sulphadoxine. Increased toxicity with quinacrine.
Action
Description: Chloroquine is used for malarial prophylaxis (as a suppressive) and in managing acute attacks of malaria. It is highly active against erythrocytic forms of P. vivax, P. malariae and P. falciparum. It influences Hb digestion by increasing intravesicular pH in malaria parasite cells and interferes with the nucleoprotein synthesis of the patient. It is also effective in extra intestinal amoebiasis. In RA chloroquine and more effectively hydroxychloroquine have a disease-modifying effect.
Pharmacokinetics:
Absorption: Rapid and complete (oral); rapid (IM/SC).
Distribution: Widely distributed; high concentrations in kidneys, liver, lungs and spleen; crosses the placenta; enters breast milk.
Metabolism: Extensively hepatic; converted to monodesethylchloroquine.
Excretion: Urine (as unchanged drug and metabolite).
Storage
Store at 15-30°C.
Disclaimer: This information is independently developed by MIMS based on Chloroquine from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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