Flashcards in Antimalarial Drugs Deck (18):
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Plasmodium Vivax
Low parasite burden, easier to take care of, mild anemia, can go into latent form for years, need radical tx. Most common outside Africa. Schuffner's dots 48 hour recurring fever
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Plasmodium Ovale
Low parasite burden, easier to take care of, mild anemia, can go into latent form for years need radicle tx. Schuffner's dots, 48 hour recurring fever
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Plasmodium Malariae
Low parasite burden, easier to take care of, mild anemia 72 hour recurring fever
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Plasmodium falciparum
Most deadly, most common in africa, high parasite burden, severe anemia, cerebral and multi-organ symptoms. gametes look like a sickle or curved banana shape. Forms a rosette and causes small vessels to clog off due and ischemia. Produces cytokine response, and can infect RBCs of any age. 24 hour recurring fever
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Order of infection
Sporozites from mosquito injected into body, migrate to liver. Enters hepatocytes and become schizonts, multiply and lyse the hepatocyte as merozoites and infect RBCs. They then enter the ring form, become trophozites, then Schizont, and lyse the RBC as Merozoites which can mature and produce gametes, or can reinfect another RBC. The Gametes reproduce in the mosquito.
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Schuffner's dots
Dots seen in the cytoplasm of cells infected by P. ovale or P vivax
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Binding site for the merozoite to enter the RBC.
Glycophorin Receptor
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Fever waxing and waining
Is due to merozoite release from the RBCs.
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Chloroquine
Prophylaxis agent or tx. inhibits heme polymerase preventing the conversion of ferriptotoporphyrin to hemozolin causing toxic buildup in the cell. Can have dizzyness, headache, skin rashes, can cause serious eye dameage in extended large doses.
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Quinine
More toxic than chloroquine, but no resistance developed, used for resistant P. falciparum. Inhibits heme polymerase. AE: tinnitus, blurred vision, nausea, headache, decreased hearing aacuity, damage to vision balance and hearing.
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Quinidine
Often combined with Quinine. Antiarrhythmic drug which blocks Na and K currents. IV for severe malaria, AE: Cardiac problems
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Mefoquine
Inhibits heme polymerase. AE: neuropsychiatric reactions (disorientation, hallucinations, depression). Used only for chloroquine resistant P. falciparum.
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Atovaquone
MOA: depolarizes parasitic mitochondria and inhibits electron transport. Usually given with proguanil. Has drug interactions.
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Proguanil
Metabolite inhibits the plasmodial Dihydrofolate reductase. Enhances mitochondrial toxicity of atovaquone. Becomes concentrated in erythrocytes.
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Atovaquone-proguanil
Combination acts to depolarize parasitic mitochondrial ETC and DHFR. Has slow onset, expensive, GI disturbances. Replacing mefoquine for prophylaxis.
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Artemisinins
Heme iron in the malarial pigment acts on the drug to produce free radicals that damage parasite proteins. Inhibits calcium ion ATPase in P. falciparum, rapid and potent effect against all. Do not use alone to prevent resistance.
Often combined with lumefantrine
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Primiquine
"radicle Care" used to treat hepatic forms of P. vivax and P. Ovale. Unknown MOA. SEE HEMOLYTIC ANEMIA IN PTs With G6P deficiency.
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