Chloroquine Phosphate

Category: Antimalarial drug
Form: Oral tablets

Uses:

• Treatment of malaria caused by Plasmodium species, including P. vivax, P. ovale, P. malariae, and chloroquine-sensitive P. falciparum.

• Prevention of malaria in people traveling to endemic areas.

• Occasionally used for autoimmune conditions like rheumatoid arthritis and systemic lupus erythematosus due to anti-inflammatory effects.

Mechanism of Action:

• Chloroquine accumulates in the food vacuole of the malaria parasite inside red blood cells.

• It inhibits heme polymerization, leading to a buildup of toxic heme that kills the parasite.

• Its immunomodulatory effects help in reducing inflammation in autoimmune diseases.

Administration:

• Taken orally, with or without food.

• Dosage depends on whether it is for treatment or prophylaxis, and on the patient’s weight and age.

• For prevention, usually taken once weekly, starting 1–2 weeks before entering a malaria-endemic area and continuing for 4 weeks after leaving.

Side Effects:

• Common: nausea, vomiting, abdominal discomfort, headache, dizziness.

• Other: itching (especially in dark-skinned individuals), mild skin rash, loss of appetite.

• Rare but serious:

  • Retinopathy or vision problems with long-term use

  • Heart rhythm disturbances (QT prolongation)

  • Severe allergic reactions

  • Blood disorders

Precautions:

• Avoid in patients with pre-existing eye disease, liver or kidney impairment.

• Long-term use requires regular eye examinations.

• Use cautiously in patients with heart conditions.

• Not recommended during pregnancy or breastfeeding unless prescribed.

• Monitor for drug interactions, especially with medications affecting heart rhythm.

Summary:
Chloroquine Phosphate is an oral antimalarial and immunomodulatory drug used to treat and prevent malaria and manage certain autoimmune conditions. It works by disrupting the parasite’s metabolism inside red blood cells. Common side effects include gastrointestinal upset, headache, and itching, while serious effects like retinopathy or heart problems are rare but require monitoring, particularly during long-term use.