continued...

When a malaria infection is caused by resistant strains of P. falciparum or P. vivax, treatment may be more difficult. When treatment with chloroquine does not work, you must take other medicines. These medicines may include:

• Malarone, which is a combination of two antimalarial medicines (atovaquone and proguanil). Malarone is taken to treat malaria caused by chloroquine-resistant P. falciparum.
• Doxycycline, for infections caused by P. falciparum and P. vivax in Thailand and Kenya.
• Quinine plus an antibiotic such as doxycycline, tetracycline, or clindamycin for most P. falciparum infections. It should not be used in Southeast Asia, where quinine effectiveness is declining. It is only somewhat effective in Thailand.
• Coartem, which is a combination of the two medicines artemether and lumefantrine. It is used to treat malaria caused by chloroquine-resistant P. falciparum.

You can get antimalarials intravenously (IV) if you are unable to take pills. IV delivery is also used for severe malaria. In the United States, quinidine is the medicine typically used in these situations.

Antimalarials to prevent recurrences

Some people have recurring flu-like symptoms for years after the initial malarial infection. Relapses from infection of P. vivax or P. ovale are the most common and can be prevented by taking primaquine.

What To Think About

• Children who weigh less than 33 lb (15 kg)should not visit an area that has a risk of chloroquine-resistant malaria.
• How effective medicines are in preventing and treating malaria depends on the medicine resistance of the parasites in the geographic location where the malaria infection occurs.
• If you are going to a location where malaria is present, it is very important to take preventive medicines and to follow the correct schedule for taking them. The majority of people who become infected with malaria did not take preventive malaria medicines or did not follow the correct dosing schedule.
• Pregnant women should discuss medicine options with their doctors.