Clit

• Malaria Treatment: Effective against acute attacks of uncomplicated malaria caused by Plasmodium vivax, P. ovale, P. malariae, and susceptible strains of P. falciparum.
• Malaria Prophylaxis: Prevention of malaria in endemic areas caused by susceptible Plasmodium species.
• Extraintestinal Amebiasis: Adjunctive treatment for liver abscesses caused by Entamoeba histolytica.
• Rheumatoid Arthritis and Lupus Erythematosus: Used off-label for its anti-inflammatory and immunomodulatory effects in autoimmune disorders, especially systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA).
• Other Investigational Uses: Explored in some viral infections and certain cancers but not yet established.

• Malaria Treatment (Adults):
• Initial dose: 600 mg base (equivalent to 1,000 mg chloroquine phosphate) orally, followed by 300 mg base (500 mg chloroquine phosphate) at 6, 24, and 48 hours after the initial dose.
• Malaria Prophylaxis (Adults):
• 300 mg base (500 mg chloroquine phosphate) once weekly, starting 1–2 weeks before entering endemic area, continued weekly during stay, and for 4 weeks after leaving.
• Pediatric Dosing:
• Dose adjusted by body weight; typical treatment dose is 10 mg base/kg on day 1, followed by 5 mg base/kg at 6, 24, and 48 hours.
• Rheumatoid Arthritis and SLE:
• Typically 250 mg to 500 mg chloroquine phosphate daily in divided doses; dosage individualized based on clinical response.
• Administration Route: Oral tablets or solution.
• Dose Adjustments:
• Use with caution in patients with hepatic or renal impairment; dose adjustment not well established but monitor closely.
• Avoid overdose; cumulative toxicity risk with prolonged use.

Chloroquine is a weak base that accumulates selectively in the acidic food vacuoles of Plasmodium parasites during their intraerythrocytic stage. It interferes with the parasite’s ability to detoxify heme, a toxic byproduct of hemoglobin digestion, by preventing its polymerization to hemozoin. The buildup of toxic heme and chloroquine-heme complexes leads to parasite death. Additionally, chloroquine exhibits immunomodulatory effects by inhibiting antigen processing and cytokine production, explaining its efficacy in autoimmune diseases.

• Absorption: Well absorbed orally, with bioavailability approximately 89%.
• Distribution: Widely distributed in body tissues, including liver, spleen, lungs, kidneys, and melanin-containing tissues; crosses the placenta and blood-brain barrier.
• Metabolism: Hepatically metabolized mainly to desethylchloroquine (active metabolite).
• Elimination: Primarily renal excretion; elimination half-life ranges from 1 to 2 months due to extensive tissue binding.
• Onset of Action: Rapid for malaria treatment, with peak plasma levels within 2–6 hours.

• Pregnancy: Category C. Crosses placenta; use only if potential benefit justifies potential risk. Malaria poses serious risk in pregnancy; chloroquine may be used when indicated.
• Lactation: Excreted in breast milk in small amounts; considered compatible with breastfeeding but monitor infant for adverse effects.

• Antimalarial agent; 4-aminoquinoline derivative.

• Known hypersensitivity to chloroquine, 4-aminoquinolines, or any excipients.
• Pre-existing retinopathy or visual field defects.
• Porphyria.
• History of chloroquine-induced hematologic or neurologic toxicity.

• Risk of retinal toxicity and irreversible vision loss with prolonged use; regular ophthalmologic monitoring recommended, especially for long-term therapy.
• Caution in patients with psoriasis or porphyria as it may exacerbate these conditions.
• Potential for cardiotoxicity including arrhythmias and conduction disorders; monitor ECG if indicated.
• Use caution in hepatic or renal impairment.
• Risk of severe hypoglycemia; monitor blood glucose in diabetic patients.
• Avoid overdose; chloroquine has a narrow therapeutic index and can be fatal in overdose.

Common:

• Gastrointestinal upset: nausea, vomiting, diarrhea, abdominal pain.
• Headache, dizziness.
• Pruritus and skin rash.

Serious/Rare:

• Retinopathy and vision changes (irreversible if untreated).
• Cardiotoxicity (QT prolongation, arrhythmias).
• Myopathy and neuromyopathy with chronic use.
• Hypoglycemia.
• Hemolysis in G6PD deficiency (rare).
• Psychosis or seizures (rare).

• Increased toxicity: With drugs that prolong QT interval (e.g., amiodarone, quinidine), increasing risk of arrhythmias.
• Reduced efficacy: Antacids, kaolin, or other agents that reduce absorption if co-administered simultaneously (separate administration times recommended).
• Potential interaction: With cyclosporine and metoprolol (increased blood levels).
• Enzyme Involvement: Not a significant CYP450 substrate but may inhibit CYP2D6.

• Resistance to chloroquine is widespread for P. falciparum malaria; WHO recommends alternative therapies where resistance is prevalent.
• Continued use for P. vivax and other sensitive species remains valid.
• New caution guidelines emphasize retinal monitoring and limiting duration of use for autoimmune indications.
• No major recent changes to malaria prophylaxis dosing; alternatives preferred in resistant regions.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from moisture and light.
• Keep container tightly closed.
• Avoid freezing.