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A 35-year-old woman comes to the emergency department because of intermittent fevers, chills, malaise, and fatigue for the past 7-days. The patient recently returned from a 2-week trip to the Dominican Republic. She was prescribed antimalarial chemoprophylaxis but forgot to take it. Past medical history is significant for seasonal allergies and “chronic joint pain”. Temperature is 38.9°C (102.0°F), pulse is 103/min, respirations are 18/min, and blood pressure is 118/70 mmHg. Physical examination shows pale conjunctiva. Laboratory evaluation shows mild anemia and thrombocytopenia. Peripheral blood smear findings are shown below. After a complete evaluation, the patient is started on hydroxychloroquine. Which of the following findings can also be managed with the medication?
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External References

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Chloroquine p. 197

malaria p. 154


chloroquine p. 197

Plasmodium spp.

chloroquine p. 197


chloroquine p. 197


chloroquine p. 197


Malaria is an infection that can be caused by a few different types of plasmodium species, which are single- celled parasites that are spread by mosquitoes.

There are hundreds of types of Plasmodium species, but the five that cause malarial disease in humans are Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale, and Plasmodium knowlesi.

Once the plasmodium gets into the bloodstream, it infects liver cells and red blood cells, which causes a variety of symptoms and sometimes even leads to death. We rely on groups of medications commonly known as antimalarials, in order to prevent and treat malaria.

Now, malaria is transmitted when a plasmodium- infected female of the Aedes, Anopheles, or Culex mosquito hunts for a blood meal in the evening and throughout the night.

They’re kind of like tiny flying vampires, with the mosquito being drawn to carbon dioxide that get breathed out, as well as bodily smells, like foot odor.

At this point, the Plasmodium is in a stage of development called a sporozoite, waiting patiently in the mosquito’s salivary gland.

When the mosquito bites a person with its proboscis, the worm- like sporozoites spill out of the mosquito’s saliva and make it into the bloodstream.

The sporozoites then travel to the liver, where they invade hepatocytes.

There, they begin asexual reproduction, also known as schizogony.

Over the next 1-2 weeks, P. falciparum, P. malariae, and P. knowlesi sporozoites multiply asexually and mature into merozoites, while host hepatic parenchymal cells die.

In contrast, Plasmodium vivax and Plasmodium ovale sporozoites enter into a dormant hepatic phase, where they are called hypnozoites.

They can remain in this dormant phase for months to years until they wake up and begin schizogony.


Antimalarials are a class of drugs used to treat or prevent malaria. Malaria is caused by parasites belonging to the plasmodium species, and can be deadly if not treated quickly. Antimalarial drugs work by killing these parasites that cause the disease. There are different types of antimalarials usually taken as pills or injections. Common brands include artemisinin, chloroquine, quinine sulfate, doxycycline, and quinine. Antimalarial drugs are effective at treating malaria, but they can have various side effects depending on the drug.


  1. "Katzung & Trevor's Pharmacology Examination and Board Review,12th Edition" McGraw-Hill Education / Medical (2018)
  2. "Rang and Dale's Pharmacology" Elsevier (2019)
  3. "Goodman and Gilman's The Pharmacological Basis of Therapeutics, 13th Edition" McGraw-Hill Education / Medical (2017)
  4. "Haem-activated promiscuous targeting of artemisinin in Plasmodium falciparum" Nature Communications (2015)
  5. "Tetracyclines Specifically Target the Apicoplast of the Malaria Parasite Plasmodium falciparum" Antimicrobial Agents and Chemotherapy (2006)

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