Malaria: Medications

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Medications

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. Therefore, if you are traveling to an area where malaria is present, it is important to consider taking medicine before you travel, while you are in the area, and after you return home to reduce the risk of infection. 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 (such as being pregnant, being elderly or young, being sick, or having immunity or resistance to malaria).
• Your ability to swallow medicine.

It is important to know which species of parasite is present because serious complications may develop 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 three species of malaria is rarely life-threatening.
• The density of parasites. If the percentage of red blood cells infected (parasite density) is over 5%, treatment may include medications given directly into a vein (intravenously, or IV) rather than medicine taken by mouth.
• Your health condition. You are at increased risk for developing 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 medication treatment of malaria, your doctor may sometimes 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) medications if there are complications or your condition worsens. 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.

Drug therapy and treatment continue to change as medication resistance increases and new medicines are developed.

Medication Choices

There are several medications for preventing and treating malaria.

Medications 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. Start treatment 1 to 2 weeks before you travel to areas where malaria is present. Continue to take it weekly during travel in areas where malaria is present and for 4 weeks after you leave these areas. You can take chloroquine to prevent P. falciparum and P. vivax infections in areas where medication resistance to chloroquine has not been confirmed.
• Mefloquine. Start treatment 1 to 2 weeks before you travel to areas where malaria is present. Continue to take it weekly during travel in areas where malaria is present and for 4 weeks after you leave these areas. Do not take mefloquine if you have a history of active or recent depression or other psychological conditions.
• Doxycycline. You can take doxycycline if you cannot take mefloquine. Start treatment 1 to 2 days before you travel to areas where malaria is present. Take it daily during travel in areas where malaria is present and for 4 weeks after you leave these areas. Women who are pregnant and children younger than age 8 should not take this medication.
• Primaquine. You take primaquine to prevent relapses of P. vivax and P. ovale. Take primaquine for 2 weeks after you leave the area where these parasites are present. (You should be tested for glucose-6-phosphate dehydrogenase deficiency before taking primaquine phosphate.)
• Malarone. Malarone is a combination of two antimalarial medications (atovaquone and proguanil HCL). Malarone is taken to prevent malaria caused by P. falciparum.⁶ Adults need to take one tablet daily 1 or 2 days before they enter an area where malaria is present and continue taking it daily throughout their stay. Then, you take it for 7 days after returning home.

Medications to treat infections

Chloroquine is the most effective medication 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 medication resistance to chloroquine has not been confirmed.

Medications 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:

• Mefloquine, for chloroquine-resistant P. falciparum infections outside of Thailand, Myanmar, and western Cambodia.
• Doxycycline, for infections caused by P. falciparum and P. vivax in Thailand and Kenya.
• Quinine sulfate 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.
• Quinine sulfate plus pyrimethamine-sulfadoxine, for chloroquine-resistant P. falciparum infections.
• Quinine sulfate plus clindamycin, given to children younger than age 8 and women who are pregnant.

You can get antimalarials directly into a vein (intravenously, or IV) if you are unable to take oral medication. IV delivery is also used when the malaria infection has progressed and may lead to permanent complications or when the infection has become life-threatening. In the United States, quinidine gluconate is the medication of choice 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 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 medication 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 medication options with their doctor.

Last updated:	May 16, 2007
Author:	Maria G. Essig, MS, ELS
Reviewed By:	Martin Gabica, MD - Family Medicine, W. David Colby IV, MSc, MD, FRCPC - Infectious Disease
Editors:	Susan Van Houten, RN, BSN, MBA, Pat Truman, MATC