chloroquine, Aralen (cont.)

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PREPARATIONS: Tablets: 250 and 500 mg


  • Antacids and kaolin can reduce absorption of chloroquine.  Administration of chloroquine and these agents should be separated by at least 4 hours.
  • Cimetidine (Tagamet) can block the breakdown of chloroquine, increasing its blood levels. This combination should be avoided.
  • Chloroquine significantly reduces blood levels of ampicillin. Ingestion of ampicillin and chloroquine should be separated by at least two hours.
  • Chloroquine may increase cyclosporine blood levels. Cyclosporine blood levels should be monitored and, if necessary, chloroquine should be stopped.
  • Combining chloroquine and mefloquine may increase the risk of seizures.
  • Chloroquine can reduce the antibody response to primary immunization with intradermal human diploid-cell rabies vaccine.

PREGNANCY AND BREASTFEEDING SAFETY: There are no studies evaluating the safety and efficacy of chloroquine in pregnant women. Use of chloroquine during pregnancy should be avoided unless it is necessary and the benefit outweighs the risk. Chloroquine is excreted in breast milk.

STORAGE: Chloroquine should be stored at room temperature, 15-30 C (59-86 F).


  • For acute malaria attacks in adults the initial dose is 1 g followed by an additional 500 mg after 6 to 8 hours, then 500 mg 24 and 48 hours after the first dose.
  • The dose for treating children is 10 mg/kg for the first dose then 5 mg/kg daily for 2 days, starting 6 hours after the first dose.
  • The dose for treating intestinal amebiasis is1 g daily for two days, followed by 500 mg daily for at least two to three weeks.
  • Chloroquine usually is combined with an effective intestinal amebicide.


  • Chloroquine is an anti-malarial drug. It is similar to hydroxychloroquine (Plaquenil) and is useful in treating several forms of malaria as well as amebiasis that has spread outside of the intestines.
  • Its mechanism of action is unknown; however, malarial parasites invade human red blood cells, and chloroquine may prevent malarial parasites from breaking down (metabolizing) hemoglobin in human red blood cells.
  • Chloroquine is effective against the malarial parasites Plasmodium vivax, P. malariae, P. ovale, and susceptible strains of P. falciparum.
  • The FDA approved chloroquine in October, 1949.

Medically reviewed by Omudhome Ogbru, PharmD

Reference: FDA Prescribing Information

Medically Reviewed by a Doctor on 1/19/2016

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