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
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
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.