Information on Chloroquine (Aralen®)

You will be spending part of your trip in an area where malaria is widespread. Malaria is an important cause of disease and death abroad. It is a blood infection caused by a parasite called Plasmodium, which is transmitted by a mosquito bite.

Malaria can be prevented by taking medication regularly. However, since no drug is 100% effective, it is important to protect yourself against mosquito bites: use an insect repellent containing DEET, sleep under mosquito netting (preferably impregnated with permethrin), avoid perfumes, wear pale colored clothes that cover most of the body, and avoid going out in the evenings and at night. These measures are just as important as taking medicines.

Chloroquine (Aralen®) is recommended at the following dosage:


  • 2 tablets per week


  • < 10 kg: 1/4 tablet per week
  • 10-19 kg: 1/2 tablet per week
  • 20-30 kg: 1 tablet per week
  • 31-45: 1 1/2 tabletd per week
  • ≥ 46 kg: adult dose

Take tablets together, always on the same day of the week, preferably just after a meal to make them easier to digest. Start taking the medication one week before departure, continue during your trip and for 4 weeks after leaving the region where malaria can be transmitted. Chloroquine is safe for pregnant women and newborns. Tablets can be crushed and mixed in with food to make them easier to take.

Side effects

Most travelers have no side effects. Occasional side effects are stomach upsets and itchiness. These reactions are usually minor and disappear when the medication is stopped. Adverse reactions can be lessened by splitting the dose in two smaller ones and taking one every 3 or 4 days (for example, 1 tablet on Monday and 1 tablet on Thursday).

In case of fever

Despite taking preventive medication, fever that occurs when traveling or in the months after your return may be a sign of malaria. See a doctor immediately and tell him or her about your recent travel to a tropical area.


Version française