Anti-Parasitic Drugs (Buxton) Flashcards
Plasmodium sp., Giardia lamblia, Entamoeba histolytica, and Toxoplasma gondii are all examples of what kind of organism?
Protozoa
Schistosoma sp. is an example of what kind of organism?
Trematode
Teania sp. is an example of what kind of organism?
Cestode
Ascaris lumbricoides, hookworms, Trichinella sp., and filarial worms are all examples of what kind of organisms?
Nematodes
A 25-year-old medical student presents with high fever and chills, severe headache, malaise and myalgia 4 days after returning from a medical mission trip to Nigeria. He took chloroquine prophylactically to prevent malaria. His blood smear is shown in the photo. What does his blood smear show and how should he be treated?
P. falciparum (banana-shaped gametocyte)
Artemisinin
What happens when plasmodium break down heme?
Plasmodia utilize amino acids from hemoglobin; leaving behind heme, which becomes very toxic when it accumulates in the cell.
What treatments for malaria are inhibitors of the parasite electron transport system?
Atovaquone
Primaquine
What treatments of malaria are inhibitors of heme metabolism?
Chloroquine
Quinine
Qunidine
Mefloquine
Artemisin
What do inhibitors of heme metabolism do?
Result in build-up of toxic heme metabolites which are lethal to the parasite
What treatments of malaria inhibit translation?
Tetracycline
Doxycycline
Clindamycin
What do inhibitors of translation for the treatment of malaria do?
Bind to 30S or 50S ribosomal subunit to prevent parasite protein synthesis
What treatments of malaria inhibit folate metabolism?
Sulfdoxine + Pyrimethamine
Proguanil
What do inhibitors of folate metabolism for the treatment of malaria do?
Inhibit parasite nucleotide synthesis
Which drugs are used for the prevention of malaria?
Atovaquone/Proguanil
Chloroquine
Doxycycline
Mefloquine
Primaquine
What does malaria treatment depend on?
Species and resistance patterns in the geographic region where the infection occurred
A 12 year old boy presents with a 1 week history of malaise, weakness, abdominal cramps and diarrhea. Upon questioning, the boy admits to feeling bloated and having excessive flatulence. The stool is grey or light colored and greasy or fatty in appearance (steatorrhea) and is not visibly bloody. He had recently returned from a week long camping trip, and admits to drinking from a stream in the area. Examination of the stool reveals the parasite shown in the photograph.
With which parasite is he infected?
Giardia lamblia
A 12 year old boy presents with a 1 week history of malaise, weakness, abdominal cramps and diarrhea. Upon questioning, the boy admits to feeling bloated and having excessive flatulence. The stool is grey or light colored and greasy or fatty in appearance (steatorrhea) and is not visibly bloody. He had recently returned from a week long camping trip, and admits to drinking from a stream in the area. Examination of the stool reveals the parasite shown in the photograph.
How is this infection treated? What do these drugs do? What other parasitic infections are treated with the same agent?
Metronidazole
Nitazoxanide
Tinidazole
All 3 drugs induce DNA damage and generate toxic radicals within the parasite
Entamoeba histolytica, Trichomonas vaginalis
A 26-year-old Peace Core volunteer in Kenya was sent home due to 4 month history of increasing upper right quadrant abdominal pain, nausea, vomiting and diarrhea. Physical exam revealed hepatosplenomegaly. The stool was positive for blood. Stool cultures were negative for bacterial pathogens; however an ova and parasite exam revealed the eggs shown in the photo.
What kind of organisms are schistosomes?
Trematodes - blood flukes
A 26-year-old Peace Core volunteer in Kenya was sent home due to 4 month history of increasing upper right quadrant abdominal pain, nausea, vomiting and diarrhea. Physical exam revealed hepatosplenomegaly. The stool was positive for blood. Stool cultures were negative for bacterial pathogens; however an ova and parasite exam revealed the eggs shown in the photo.
How is this infection treated? What is the mechanism of action for this drug? What else can it treat?
Praziquantel
Increases parasite membrane permeability to calcium, resulting in parasite muscle contraction and paralysis
Can treat tapeworm & trematode infections, e.g. Echinoccus sp., Tania solium, Schistosoma sp.
While on a medical mission along the Amazon River in Peru, several children in a village present with varying degrees of abdominal discomfort. Ova and parasite exam results from stool are shown in the photographs.
With which parasites are they infected? What kind of parasites are these?
Nematodes - Ascaris, Ancyclostoma, Trichuris
