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Malaria Drugs


Malaria is a serious, often deadly disease transmitted by mosquitoes. It affects about 300 million people and causing 1 million deaths a year. More than 90 percent of cases occur in tropical Africa, with young children and pregnant women being the most impacted. In Africa, malaria is the leading cause of death for children under age five [Source: Roll Back Malaria Partnership].

If you conract malaria while traveling in a tropical country, you have to get to a medical facility immediately. Malaria is curable with accurate diagnosis and timely treatment. Learn about the latest approaches and preventive actions you can take before you leave home.

Depending on which country you are visiting, you will be exposed to different types of Plasmodium parasites transmitted by the female Anopheles mosquito:

  • P.falciparium - the most deadly of the four types and the leading cause of malarial deaths in Africa
  • P. vivax - the dominant malaria species outside Africa and is prevalent in areas in the Middle East, Asia, Oceania, and Central and South America
  • P. malariae and P. ovale - generally less common but found worldwide, especially in the tropical areas of Africa

Timely diagnosis and treatment can prevent worsening of symptoms and the spread of the disease to other people. Each of the four types of malaria parasites has distinguishing characteristics that can be identified by examining a drop of blood under a microscope. As some types impact both the blood and the liver and some have become resistant in some areas of the world to the most widely used antimalarial drug, accurate identification of the organism is essential to prescribing an effective treatment.

Blood Image Gallery


Photo courtesy Dr. Mae Melvin/CDC
A photomicrograph of a blood smear showing red blood cells that contain developing P. vivax parasites
(magnified 1000 times). See more blood pictures.


Malaria is curable if the right drugs are used for the correct period of time. The Centers for Disease Control and Prevention (CDC) recommend that treatment be initiated immediately and take into consideration:

  • The type of infecting Plasmodium species - Different species have varying courses of infection and drug resistance patterns in differing geographic regions. To learn more about the different species, check out How Malaria Works.
  • The severity of symptoms - Patients with uncomplicated malaria can be effectively treated with oral antimalarial drugs, while those with severe, or complicated malaria symptoms typically require hospitalization and administration of drugs by healthcare personnel.
  • The geographical area where the infection was acquired - The location informs the doctor of the likelihood of drug resistance of the infecting parasite and allows for the selection of an appropriate treatment.

Next, we'll look at the different malaria drug combinations prescribed by doctors.

The Tree Bark Cure

­The first effective treatment for malaria was the bark of the cinchona tree, which grows on the slopes of the Andes. The tree bark was used in Peru to control malaria and was introduced into Europe by the Jesuits in the 1600s.

French chemists extracted the active ingredient, quinine, from the bark in 1820, and the drug was a common treatment for malaria until replaced by chloroquine.

Quinine is now back in favor for treating severe P. falciparum, which has developed resistance to chloroquine and for treating pregnant women in the second and third trimesters.

­

Malaria Drug Combinations

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.

Artemesia annua
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:

  • Artemether-lumefantrine
  • Aartesunate + amodiaquine
  • Artesunate + mefloquine
  • Artesunate + sulfadoxine-pyrimethamine
Complicated cases are treated with rectal, intramuscular or intravenous drugs:
  • Artesumate, artemisiin or arthemeter
  • Quinine

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.

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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:

Trimester
Drugs
First
Quinine + clindamycin
Second and Third
ACT known to be effective in the country/region
Artesunate + clindamycin
Quinine + clindamycin


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.

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More Great Links

Sources

  • "Diagnosis." CDC.
    http://www.cdc.gov/malaria/diagnosis_treatment/diagnosis.htm
  • "Frequently Asked Questions About Malaria." CDC.
    http://www.cdc.gov/malaria/faq.htm
  • "Frequently-Asked-Questions about Malaria." Roll Back Malaria.
    http://www.rollbackmalaria.org/
  • "Guidelines for the Treatment of Malaria." WHO.
    http://www.who.int/malaria/docs/TreatmentGuidelines2006.pdf
  • "Malaria." Global Health Reporting.
    http://www.globalhealthreporting.org/malaria.asp
  • "Malaria." The Special Programme for Research and Training in Tropical Diseases (TDR).
    http://www.who.int/tdr/index.html
  • "Malaria." World Health Organization.
    http://www.who.int/topics/malaria/en/
  • "Part 2: Treatment: General Approach & Treatment: Uncomplicated Malaria." CDC.
    http://www.cdc.gov/malaria/diagnosis_treatment/clinicians2.htm
  • "Regional Malarial Information". CDC.
    http://www.cdc.gov/travel/regionalmalaria/cafrica.htm#antimalarialdrugs