Drug information of Chloroquine

Chloroquine

Drug group: Antimalarials

chloroquine is a 4-aminoquinoline compound for oral administration . chloroquine is an antimalarial and amebicidal drug .It has also been used to treat rheumatoid arthritis, systemic lupus erythematosus, and in the systemic therapy of amebic liver abscesses.

Mechanism of effect

the drug can inhibit certain enzymes, its effect is believed to result, at least in part, from its interaction with DNA. However, the mechanism of plasmodicidal action of chloroquine is not completely certain.

Pharmacodynamic

Chloroquine is the prototype anti malarial drug, most widely used to treat all types of malaria except for disease caused by chloroquine resistant Plasmodium falciparum .

Chloroquine inhibits the parasitic enzyme heme polymerase that converts the toxic heme into non-toxic hemazoin, thereby resulting in the accumulation of toxic heme within the parasite. It may also interfere with the biosynthesis of nucleic acids.

Pharmacokinetics

  • Absorption

-         Bioavailability: ~89%

-         Peak plasma time: 1-2 hr 

  • Distribution

Distributed widely in body tissues (eg, eyes, heart, kidneys, liver, lungs) where retention prolonged; crosses placenta; enters breast milk

  • Metabolism

Partially in liver

  • Elimination

-         Half-life: 3-5 days

-         Excretion: urine (~70% as unchanged drug); acidification of urine increases elimination

-         Small amounts may be present in urine months following discontinuation of therapy

Drug indications

malaria

Dosage

  • Adult

Malaria

Prevention: 500 mg (300 mg base) PO once/week

Non-chloroquine-resistant

  • 1 g (600 mg base) PO, THEN
  • 500 mg (300 mg base) PO 6-8 hours later, THEN
  • 500 mg (300 mg base) PO at 24 hours & 48 hours after initial dose

Amebiasis, Extraintestinal

1 g (600 mg base) PO qDay for 2 days, THEN

500 mg (300 mg base) qDay for 14-21 days

Porphyria CutaneaTarda (Off-label)

125-250 mg (75-150 mg base) PO twice weekly

  • Pediatric:

Malaria

Prophylaxis: 5 mg/kg PO q1Week 

Treatment

  • 1st dose: 10 mg/kg PO x1 dose
  • 6 hours after 1st dose: 5 mg/kg PO qDay x2 days

Porphyria CutaneaTarda (Off-label)

Dosing schedules not well established in children

Drug contraindications

hypersensitivity to this drug

Alerts

  • Shown to cause severe hypoglycemia including loss of consciousness that could be life-threatening in patients treated with or without antidiabetic medications. patients presenting with clinical symptoms suggestive of hypoglycemia during treatment with chloroquine should have blood glucose level checked and treatment reviewed as necessary.
  • May cause hemolysis in glucose-6 phosphate dehydrogenase (G-6-PD) deficiency; blood monitoring may be needed as hemolytic anemia may occur, in particular in association with other drugs that cause hemolysis.
  • Monitor CBC periodically with prolonged therapy.
  • Caution with history of auditory damage.
  • Caution with hepatic disease, alcoholism, and coadministration with other hepatotoxic drugs.
  • May provoke seizures in patients with history of epilepsy.
  • Irreversible retinal damage observed in some patients, monitoring should include annual ophthalmological examinations.
  • May exacerbate heart failure.
  • Cases of cardiomyopathy resulting in cardiac failure.
  • QT interval prolongation, torsades de pointes, and ventricular arrhythmias reported.
  • Points of recommendation
  • Take this medication by mouth, usually with food to prevent stomach upset
  • Take this medication 4 hours before or after taking a certain drug for diarrhea (kaolin) or taking antacids (such as magnesium/aluminum hydroxide).
  • Do not stop taking it before completing treatment, even if you feel better, unless directed to do so by your doctor.
  • If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.


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