The affordable and accessible antimalarial drug, chloroquine, was the mainstay treatment for uncomplicated P. falciparum, but it has become ineffective because the parasites have developed resistance to the drug. The World Health Organization (WHO) now recommends Artemisinin Combination Therapy (ACT), in which artemisinin is combined with one or more drugs.
Artemisinin is isolated from the shrub Artemisia annua, long used in traditional Chinese medicine. Artemisinin and its derivatives (artesunate, artemether, artemotil and dihydroartemisinin) have been shown to be a safe and effective treatment for malaria in Southeast Asia. Because artemisinin rapidly loses its effectiveness, it is combined with longer-acting drugs. Researchers anticipate that the combination approach will also diminish the parasite's ability to develop resistance to the drugs.
Photo courtesy Eurobodalla Shire Council
Artemesia annua, or Chinese wormwood, is a source of artemisinin, a safe and effective treatment for malaria in Southeast Asia.
For treating uncomplicated P. falciparum malaria, the World Health Organization (WHO) recommends the following oral ACTs:
- Aartesunate + amodiaquine
- Artesunate + mefloquine
- Artesunate + sulfadoxine-pyrimethamine
- Artesumate, artemisiin or arthemeter
Additional treatment is also necessary for symptoms of complicated malaria, which may include coma, convulsions, severe anemia, low blood sugar, fluid-filled lungs (pulmonary edema) and acute kidney failure.
Treating P. vivax and P. ovale
P. vivax and P. ovale reside in both the red blood cells and the liver. A complete cure requires getting rid of the parasites in both sites to avoid a releapse. Primaquine targets the liver, while chloroquine or amdiaquine targets the blood.
The following drugs are currently recommended by the WHO:
- Chloroquine + primaquine
- Amdiaquine + primaquine for chloroquine-resistant P. Vivax
Severe cases of these types of malaria are rare, but when they occur they should be treated in the same manner as severe P. falciparum malaria.
Treating P. malariae
The WHO-recommended treatment for P. malariae is chloroquine.
Treating Mixed Malaria Infections
Mixed malarial infections are common. For example, although malaria transmission levels are low in Thailand, one-third of patients with acute P. falciparum are co-infected with P. vivax.
The WHO recommends ACTs for mixed infections and primaquine for patients co-infected with P. vivax and P. ovale.
Treating Pregnant Women
Pregnant women are particularly vulnerable to malaria and require different treatment for particular stages of the pregnancy. The WHO recommends the following treatment for pregnant women:
Currently there is no vaccine available to protect against malaria, although research efforts are underway to develop one. The CDC has a Web site where you can find out which drugs will protect you from malaria in which regions of the world. If you're planning a trip to a tropical area, visit CDC Traveler's Health: Anti-malarial Drugs to learn which prescription drugs you will need to get from a doctor before you leave.
For lots more information on malaria drugs, malaria and related topics, check out the links on the next page.