Antiparasitic V.txt

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Antiparasitic V.txt
2012-04-29 01:06:39

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  1. What protozoa are covered by metronidazole?
    Giardia, Entamoeba, and Trichomonas
  2. What is the MOA?
    Inhibits many cellular processes including DNA replication
  3. What are its pharmacokinetic properties?
    • Given oral, IV, or topical
    • Distributes widely, including CSF and metabolized by liver (potential interactions)
  4. What are its toxicities?
    • Disulfiram-like rxn
    • Metallic taste, redish urine
    • Teratogenic
  5. When is iodoquinol used and its toxicities?
    • Luminal trophozoites of Entamoeba
    • Side effects (rare): skin rxns, thyroid enlargement, HA, diarrhea
  6. When is paromomycin effective?
    Luminal Entamoeba and Trichomonas (it is an aminoglycoside)
  7. Aminoglycoside reminder:
    • Aminoglycoside abx: binds 30S subunit and blocks initiation, translation, and causes incorporation of incorrect AA
    • Not absorbed orally, no CNS penetration, excreted by kidney
    • Toxicity: nephrotoxic, ototoxic
    • Resistance: enzymes that adenylate, phosphorylate, or acetylate the Rx
  8. When can quinacrine be used and what is its MOA?
    Tx of Giardia; binds DNA (has been replaced by metronidazole)
  9. When can tetracyclines be used and their MOA?
    Kill bacteria that Entamoeba and Giardia need to survive
  10. What is the DOC for pneumocystosis?
  11. What is the TMP-SMX MOA?
    • Inhibits folate synthesis
    • SMX: binds dihydropteroate synthetase
    • TMP: binds DHF reductase
  12. What are the side effects?
    Stevens-Johnson syndrome, rash, cytopenias
  13. What can be used to offset the hematologic toxicity of folic acid antagonists?
    Leucovorin (exogenous THF)
  14. What is an alternative to those who can't tolerate TMP-SMX?
  15. How is it given?
    IM or nebulization
  16. What is the DOC for toxoplasmosis?
    Pyrimethamine + sulfadiazine
  17. What is another choice of pneumocystosis Tx in pts who can't tolerate TMP-SMX?
    • Atovaquone + proguanil (Malarone)
    • When are laxatives indicated along c antihelminthics?
    • Tx of T. solium to flush adult worm before proglotids release their eggs
  18. What are the important roundworms (nematodes)?
    • 1. Ascaris lumbricoides
    • --> Eggs visible in feces, intestinal infection, Loeffler's eosinophilic pneumonitis

    • 2. Enterobius vermicularis (pinworms)
    • --> Egg ingestion, perianal pruritis, scotch tape test

    • 3. Necator americanus
    • --> Larvae penetrate skin of feet, intestinal infxn can cause Fe deficiency anemia

    • 4. Trichinella spiralis
    • --> Ingestion of undercooked meat, larvae encyst in muscle causing myalgia, periorbital edema
  19. Reminder: T. solium
    • Ingestion of larva in undercooked pork --> intestinal tapeworm
    • Ingestion of eggs --> cysticercosis and neurocysticercosis
  20. What are the blood flukes?
  21. What is the DOC for roundworms, whipworms, hookworm, pinworm, and trichinosis?
  22. What is its MOA?
    Binds tubulin and interferes c protein fxn
  23. What is its distribution?
    Only 10% absorbed from GI tract
  24. What is the worst side effect?
  25. What is the 2nd option for roundworms, pinworms, and hookworm?
    Pyrantel pamoate
  26. What is its MOA?
    Cholinesterase inhibitor that causes depolarizing neuromuscular block in the worm
  27. What is the DOC of all tapeworms and the exception?
    Niclosamide (NOT the DOC for T. solium)
  28. What is the MOA?
    • Inhibits anaerobic, oxidative phosphorylation in the worm
    • Causes spasm --> worm releases from intestinal wall
  29. How can it be used to treat T. solium?
    Given c laxatives to dec. risk that ova might cause cysticercosis (Tx c albendazole)
  30. What is the DOC for all flukes (Schistosomes)?
  31. What is the praziquantel MOA?
    Inc Ca permeability leads to contraction and paralysisUse caution if you have an infection in delicate area (eye) where contraction can cause damage
  32. What 2 Rx can be used for neurocysticercosis?
    Praziquantel and albendazole