Pharm - Antiprotozoal Drugs Part 2 Flashcards
primaquine is used to eradicate ____ forms of ___ and ____
DORMANT forms of VIVAX and OVALE
explain the MOA of primaquine
it is active against ___ ___ forms
primaquine produces an electrophile that creates oxidative stress to kill the parasite
active against LATENT HEPATIC forms
true or false
primaquine is only active against hepatic forms
TRUE
primaquine is used in combination with _____to prevent _____
chloroquine (erythrocytic forms)
to prevent RELAPSE
some AE of primaquine
methemoglobinemia in G6PDH deficiency, hemolysis
leukpenia, cardiac arrythmia, etc
atavoquone MOA
disrupts the mitochondrial electron transport chain of the parasite – can’t generate ATP
atovaquone is active against ___ and ___ schizonts
blood and tissue
resistance mechanism for atovaquone and what can reduce the ressitance
SNP in the mitochondrial cytochrome b gene
administering atovaquone with proguanil decreases resistance
MOA of pyrimethamine and proguanil
selectively inhibits plasmodial DHFR – thus inhibiting folate biosynthesis and the synthesis of thymine – 1/4 of the building blocks of DNA
what are pyrimethamine and proguanil administered with and why
sulfa drugs!
they block DHPS (dihydropteroate synthase)
___ (how many) main mechanisms of resistance drive plasmodium resistance to antimalarial drugs:
give example of each
- efflux of the drug away from its site of action (ie - pfcrt in chloroquine resistance)
- change in the target due to mutations in the corresponding genes (ie - DHFR and DHPS mutation in sulfadoxine-pyrimethamine resistance)
in which targeted stage of the malarial life cycle are there more mutations/resistance and why?
the blood/erythrocytic stage
parasite is getting a lot more nutrients
chemically, what are metronidazole/tinidazole
nitroimidazoles
MOA of nitroimidazoles like metronidazole and tinidazole
inhibits nucleic acid synthesis by disrupting DNA and causing strand breakage
nitroimidazoles are the drug of choice for ___ ___
extraluminal amebiasis
common/rare AEs of nitroimidazoles
any BBW
common - nausea, dry mouth, metallic taste
rare - pancreatitis CNS toxicity
BBW = possible carcinogenic effect (shown possible in animals)
can metronidazole be used in pregnant women
NO
iodoquinol is halogenated _________
hydroxyquinolone
MOA of iodoquinol
interferes with heme metabolism of protozoa
cautions w iodoquinol
neuropathy, discontinue if any signs of iodine toxicitiy
in general what is paromomycin sulfate and what is it used for
an aminoglycoside antibiotic
used as a luminal amebicide
toxicity of paromomycin
causes renal toxicity in pts with renal insufficiency (aminoglycoside antibiotic!)
*Artemisinin-based combination therapies are recommended by the WHO for treating WHICH TYPE OF MALARIA
plasmodium falciparum malaria
which of the following antimalarial drugs are SAFE in pregnancy
quinine
chloroquine
atovaquone-proguanil
artemether-lumefantrine
all are safe except artemether - lumefantrine
what drug is effective against the LIVER STAGE of plasmodium vivax and plasmodium ovale
primaquine
hypnozoites
liver stage
MOA of chloroquine in treating malaria
interferes with hemoglobin metabolism in the parasite
(Hz - non toxic form - cannot be produced)
what antimalarial drug is known for causing vivid dreams and other neuropsych side effects
mefloquine
