52: Antiparasitic Drugs Flashcards
(45 cards)
parasites are _____, just like us
eukaryotic
similar to pyruvate dehydrogenase in aerobic organisms, ______ catalyzes the conversion f pyruvate to Acetyl CoA
PFOR
eukaryotes do not have PFOR, but giradiasis, amebiasis, and trichomoniasis do
MOA metronidazole
acitvate under anaerboic conditions by PFOR –> disrupts prtn and DNA structure and function
side effects/contraindications for metronidazole
avoid alcohol
safe preggers
little host toxicity
how do you use metronidazole to treat tichomoniasis, giardiasis, and amebiasis?
7 d. oral - treat sexual partners simultaneously
tid X 5d.
tid x 7-10 d and follow with more potent (iodoquinol or paromomycin) to eradiacate non-invasive cyst forms
drug of choice for treating symptomatic amebiasis
metronidazole
effective at eliminating trophozoite and cyst forms of e. histolytic from the lumen of intestine
iodoquinol
no activity against trophozoite forms in tissue
caution with children - optic atrophy and vision loss
treat symptomatic amebiasis
asymptomatic/mild
metronidazole follow with iodoqunol or paromomycin
iodoquinol or paromomycin
MOA paromomycin
aminoglycoside antibiotic –> inhibits prtn sysnthesis in bacteria
effective at eliminating both trophozoite and cyst forms of e. histolytica from lumen of intestine
no activity against forms that have invaded tissue
symptoms of crytosporidiosis
profuse watery diarrhea - rehydrate healthy ppl, chronic/fatal in AIDS ppl
MOA nitazoxanide
interferes with PFOR
use nitazoxanide to treat…
crytosporidiosis and giardiasis
inhibitors of folate synthesis used to treat pneumocystis jirovecii and tozoplasma gondii respectivley
TMP-SMX
Pyrimethamine-sulfadiazine
we scavenge folate from diet, parasitic protozoa must synthesize their own
MOA sulfonamides (sulfadiazine, sulfamethoxazole)
PABA analogs that inhibit the production of pteroic acid from PABA by the enzyme dihydropteroate synthase
prevents synthesis of folate
MOA diaminopyrimidibe (pyrimethamine, trimethoprim)
inhibitors of the enzyme DHFR
prevent the formation of tetrahydrofolate (the functional form of folate)
key adverse reactions to sulfonamides
rash
_______ often coadministered with pyrimethamine-sulfadiazine treatment to avoid folate deficiency
leucovorin
treatment of choic for toxoplasmosis
pyrimethamine-sulfadiazine
higher for active; lifelong lower
do not effect dormant tissue cyst
used to treat pneumocystis jirovecii infection
trimethoprim-sulfamethoxazole
higher dose for active- lifelong lower dosese
MOA chloroquine
interfere with parasite’s ability to detoxify compounds generated durign degradation of hemoglobin
trouble with chloroquine
widespread resistance issues
MOA quinine
localizes to digestive vacuoles - interfere with hemoglobin degradation or detoxification of metabolic products
may complex with parastie DNA, interfering with transcription and replication
poorest theraputetic:toxic ration for antimalarials
quinine
causes cinchonism and hypoglycemia
which antimalarial may give you hallucinations and crazy dreams?
mefloquine
