Chloroquine sulfate or phosphate oral

Therapeutic action

Antimalarial.

Indications

Given that resistance of P. falciparum to chloroquine is widespread, this drug must not be used for the treatment of falciparum malaria.

• Treatment of malaria due to chloroquine-sensitive P. vivax.
• Treatment of malaria due to P. ovale, P. malariae, and P. knowlesi.

Forms and strengths

The dose written on labels is sometimes in chloroquine salt and sometimes in chloroquine base, which leads to frequent confusion. WHO recommends prescriptions and labels in chloroquine base.

155 mg base is approximately 200 mg sulfate and approximately 250 mg phosphate or diphosphate.

• 155 mg chloroquine base tablet.

Dose and duration

• Child and adult: day 1, 10 mg base/kg.
• Child and adult: day 2, 10 mg base/kg.
• Child and adult: day 3, 5 mg base/kg.

Contra-indications, adverse effects, precautions

• Do not administer to patients with retinopathy.
• May cause gastrointestinal disturbances, headache, transitory pruritus lasting 72 hours, allergic reactions such as urticaria and angioedema, and visual disturbances.
• If the patient vomits within 30 minutes after administration, re-administer the full dose.
• If the patient vomits between 30 minutes and 1 hour after administration, re-administer half of the dose.
• There is a narrow margin between the therapeutic and toxic dose. Doses of 20 mg base/kg in children and 2 g base in adults are considered toxic.
• Avoid combination with drugs that prolong the QT interval, including amiodarone, other antimalarials, antipsychotics, fluconazole, fluoroquinolones, hydroxyzine, macrolides, and ondansetron.
• Do not administer simultaneously with antacids or calcium carbonate; administer 2 hours apart.
• Pregnancy: no contra-indication.
• Breast-feeding: no contra-indication.