You can take medicines called antimalarials to prevent and treat malaria. Malaria is a very serious disease, and its presence in many regions of the world is well known. So if you are traveling to an area where malaria is present, it is important to reduce the risk of infection by taking medicine before you travel, while you are in the area, and after you return home. Which medicine you take is based on:
- The country or areas in which you will be traveling.
- The resistance of malaria parasites to certain medicines in the area where you will be traveling.
- Your health condition (for example, whether you are pregnant, elderly or young, sick, or have immunity or resistance to malaria).
It is important to know which species of parasite is present, because serious complications may develop rapidly in a person who is infected with Plasmodium (P.) falciparum. Drug treatment is based on:
- The species of parasite. If you are infected with P. falciparum, life-threatening complications can develop rapidly. Infection caused by one of the other four species of malaria parasite is rarely life-threatening.
- The density of parasites. If the percentage of red blood cells infected (parasite density) is over 5%, treatment may include medicines given directly into a vein (intravenously, or IV) rather than medicine taken by mouth.
- Your health condition. You are at higher risk for having complications if you are pregnant, elderly, very young, or have a weak immune system. Different medicines may be prescribed for people in these groups.
- Drug resistance in the geographic area where the infection occurred. For instance, in many areas P. falciparum is resistant to the drug chloroquine.
During malaria treatment, your doctor may do daily blood smears to follow the course of the infection. Most medicines for malaria are ones you take by mouth. But you might get intravenous (IV) medicines if there are complications or your condition gets worse. If there are no complications, your fever will clear in 36 to 48 hours. And most parasites will disappear from your blood within 2 or 3 days.
The medicines used may change as malaria parasites develop resistance and as new medicines are developed.
There are several medicines for preventing and treating malaria.
Medicines to prevent malaria
A doctor or local health department can consult the CDC for specific treatment guidelines for your travel destination. Standard medicines for preventing malaria include:
- Chloroquine. You can take chloroquine to prevent P. falciparum and P. vivax infections in areas where medicine resistance to chloroquine has not been confirmed.
- Doxycycline. You can take doxycycline if you cannot take mefloquine. Women who are pregnant and children younger than age 9 should not take this medicine.
- Malarone. Malarone is a combination of two antimalarial medicines (atovaquone and proguanil). Malarone is taken to prevent malaria caused by P. falciparum.
- Mefloquine. You can take mefloquine to prevent malaria infections unless the malaria parasite in the area you're visiting is resistant to mefloquine. Do not take mefloquine if you have a history of active or recent depression or other mental illness, seizures, or some types of heart-rhythm problems.
- Primaquine. You take primaquine to prevent relapses of P. vivax and P. ovale malaria. You should be tested for glucose-6-phosphate dehydrogenase deficiency before taking primaquine.
Medicines to treat infections
- Chloroquine is the most effective medicine for treating a malaria infection caused by P. ovale or P. malariae parasites. To prevent relapses of infections caused by these two parasites, continue taking chloroquine after you leave the area where these parasites are present. Chloroquine is also used to treat P. falciparum and P. vivax infections in areas where resistance to chloroquine has not been confirmed.
- Coartem is a combination of the two medicines artemether and lumefantrine. It is used to treat malaria caused by P. falciparum.
Medicines to treat chloroquine-resistant infections
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:
- Coartem, which is a combination of the two medicines artemether and lumefantrine. It is used to treat malaria caused by chloroquine-resistant P. falciparum.
- Doxycycline, for infections caused by P. falciparum and P. vivax in Thailand and Kenya.
- Malarone, which is a combination of two antimalarial medicines (atovaquone and proguanil). Malarone is taken to treat malaria caused by chloroquine-resistant P. falciparum.
- Quinine plus an antibiotic such as clindamycin, doxycycline, or tetracycline 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.
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 malaria 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.