anti parasite drugs; antivirals Flashcards Preview

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Flashcards in anti parasite drugs; antivirals Deck (18):

chloroquine MOA

blocks detoxification of heme into hemozoin. heme accumulates and is toxic to plasmodia


chloroquine use

treast plasmodial species other than P. falciparum. doesn't work for P falciparum becasue of a membrane pump that decreases the intracellular concentration of the drug (falciparum should be treated with artemether/lumefantrine or atovaquone/proguanil).


chloroquine toxicity

retinopathy, pruritis,


zanamivir: mechanism and clinical use

inhibits flu neuraminidase: decreases the release of progeny virus.
used to treat and prevent flu A and B
oseltamivir also works this way


ribavirin: mechanism and clinical use

inhibits synthesis of guanine nucleotides by competitively inhibiting inosine monophosphate dehydrogenase.
used for RSV and hepC


ribavirn: toxicity

hemolytic anemia, severe teratogen


acyclovir: others, mechanism

others includ famciclovir, valacyclovir. this drug is monophosphorylated by HSV/VSV thymidine kinase and not phosphorylated in uninfected cells, so there are few adverse effects. it is a guanosine analog that inhibits viral DNA pol by chain termination.


acyclovir: use, considerations

used for HSV and VZV; weakly useful against EBV. no activity against CMV. no effect on latent forms of HSV and VZV. valacyclovir is a prodrug of acyclovir with better oral availability


toxicity and resistance for acyclovir

can cause crystalline nephropathy and acute renal failure. resistance by mutated viral thymidine kinase.


ganciclovir mechanism

5' monophsphate formed by a CMV viral kinase. this is a guanosine analog. it preferentially inhibits viral DNA pol.


ganciclovir use and resistance

CMV, esp. in immunocompromised pts. valganciclovir is a prodrug with better oral availability. resistance by mutated CMV DNA pol or lack of a viral kinase


gancyclovir toxicity

leukopenia, neutropenia, thrombocytopenia, renal toxicity. more toxic than acyclovir


foscarnet: mechanism

viral DNA pol inhibitor that binds to the pyrophospate binding site of the enzyme. doesn't require viral kinase activation. resistance by mutated DNA pol.


foscarnet use

CMV retinitis in immunocompromised when ganciclovir fails. good for asyclovir resistant HSV.


toxicit of foscarnet



cidofovir mechansim

preferentially inhibits viral DNA pol. doesn't require phosphorylation by a viral kinase.


cidofovir use

CMV retinitis in immunocompromised pts; acyclovir resistant HSV. long half life.


toxicity of cidofovir

nephrotoxicity. coadminister with pronebecid (incr. uric acid excretion in urine) and IV saline to decr. toxicity