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55 Cards in this Set
- Front
- Back
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MC parasitic infxn in US
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enterobius
(pinworm, nematode) |
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albendazole - tx for?
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nematode infxns
(ascariasis, trichuriasis, hookworms, pinworms) |
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albendazole - MoA?
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inhibits microtubule synthesis --> results in decreased glucose uptake and ATP synth
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albendazole - drug type?
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benzimidazole carbamate
active metabolite (albendazole sulfoxide) is generated in liver excreted in urine |
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albendazole - side effects?
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TERATOGENIC!!!
typical side effect is GI distress, but high does can lead to bone marrow suppression (hematologic toxicity in those with hepatitis) |
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mebendazole - tx for?
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nematode infxn
(ascariasis, trichurias, hookworm, pinworm) |
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mebendazole - drug type?
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synthetic benzimidazole
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mebendazole - MoA?
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inhibits microtubule synthesis
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mebendazole - side effects?
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TERATOGENIC!!!
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diethylcarbamazine - tx for?
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filiarasis, loiasis, tropical eosinophilia
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diethylcarbamazine - urine pH?
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plasma t1/2 is 2-3h if urine is acidic
plasma t1/2 is 10h if urine is alkaline |
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diethylcarbamazine - MoA?
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microfilariae become more susceptible to host defenses
mechanisms suggested - vasoconstriction - enhanced neut aggregation |
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ivermectin - tx for?
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strongyloidiasis and onchocerciasis
(nematodes) |
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ivermectin - drug type?
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semisynthetic macrocyclic lactone derived from the soil actinomycete, streptomyces avermitilis
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ivermectin - MoA?
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Activates glutamate-gated Cl ion channels and enhances GABA-mediated transmission of signals in peripheral nerves of nematodes.
Cl- influx, hyperpolarization, paralysis |
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ivermectin - excretion?
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excreted in feces
t1/2 is 16h |
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mazzotti rxn
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tx (ivermectin) may cause hypersensitivity rxn to dying microfilariae due to release of parasitic antigens
*fever, pruritis, arthralgia, HA tx = corticosteroids |
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praziquantel - tx for?
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all schistosome spp (trematodes/flukes) and most other trematodes and cestodes
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praziquantel - drug type?
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synthetic isoquinolone pyrazine
(t1/2 < 2h) |
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praziquantel - MoA?
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increases calcium permeability leading to paralysis
**dislodged and expelled |
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alternative tx for schistosoma mansoni
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oxamniquine
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alternative tx for cestode infxn
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niclosamide
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pyrantel pamoate - tx for?
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*broad spectrum*
pinworm, ascaris, hookworm (not effective against trichuriasis or strongyloidiasis) |
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pyrantel pamoate - drug type?
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tetrahydropyrimidine derivative
**poorly absorbed, active against luminal organisms |
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pyrantel pamoate - MoA?
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neuromuscular blocking (@NMJ)
causes Ach release and inhibition of cholinesterase --> paralysis and expulsion |
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permethrin - MoA?
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blocks Na currents in (ecto)parasite neurons --> paralysis
**resistance is an issue |
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malathion - MoA?
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inhibits cholinesterase in most eukaryotes (ectoparasites)
paralysis in insect (and in pt if overdosed) |
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four species of plasmodium
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p. falciparum
p. vivax p. malariae p. ovale |
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tissue schizonticides - malaria
(drug classification) |
eliminate developing or dormant liver forms
(primaquine) |
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blood schizonticides - malaria
(drug classification) |
act on erythrocytic parasites
(chloroquine, quinine, mefloquine, pyrimethamine, proguanil) |
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gametocides - malaria
(drug classification) |
kill sexual stages and prevent transmission to mosquitoes
(primaquine) |
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doc - malaria tx and prophylaxis
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chloroquine
**drug resistance is an increasing concern |
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chloroquine - pharmacokinetics
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a 4-aminoquinoline formulated as a phosphate salt for oral use
- absorbed from GI tract - max plasma conc in 3h - excreted in urine - t1/2 1-2 mo |
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chloroquine - MoA
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blood schizonticide
concentrates in the food vacuole where it prevents polymerization of hemoglobin breakdown product, heme, into hemozoin. |
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chloroquine - contraindications
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- psoriasis or porphyria
- retinal abnormalities - myopathy - kaolin (anti-diarrheal) and calcium/magnesium antacids reduce resorption |
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quinine & quinidine - origin?
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derived from the bark of the cinchona tree in S America
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quinine & quinidine - pharmacokinetics
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rapid absorption, peak in plasma by 1-3 hours
- t1/2 = 18h in severe infxn - t1/2 = 11h in healthy *****due to inc protein binding metabolized in liver, excreted in urine **quinidine has shorter t1/2 due to dec protein binding |
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quinine - MoA
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unknown - similar to choloroquine?
- blood schizonticide (against 4 spp) - gametocidal (p. vivax, p.ovale) - not active against liver stage |
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quinine - effective against...?
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p. falciparum
usu given c doxy to reduce duration to 3d. not used prophylactically - tox! |
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quinine - adverse effects
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tinnitus, HA, nausea, dizziness, flushing, visual disturbance
**QT prolongation common --> cardiac arrest and convulsions |
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mefloquine - effective against??
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cholorquine-resistant strains of p. falciparum
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mefloquine - pharmacokinetics
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synthetic 4-quinoline methanol (related to quinine)
oral only peak plasma conc 18h t1/2 = 20d (weekly for proph) |
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mefloquine - MoA
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unknown (similar to chloroquine?)
blood schizonticide |
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mefloquine - treatment
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prophylaxis
**not indicated for severe infections, quinine preferred because of more rapid activity and resistance is less likely |
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mefloquine - adverse effects
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nausea, vomiting, dizziness, sleep and behavioral disturbanecs
**contraindications epilepsy, psych, cardiac, G6PD deficiency |
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primaquine - effective against?
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effective against liver forms and gametocidal
**not effective against erythrocytic forms |
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primaquine - pharmacokinetics
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8-aminoquinoline
oral rapid absorption peak in plasma by 1-2h T1/2 = 3-8h rapidly metabolized excreted in urine |
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primaquine - MoA
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unknown
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primaquine - adverse effects
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generally well tolerated
hemolysis in G6PD-deficient avoid in myelosupression avoid in pregnancy |
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pyrimethamine & proguanil - use
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typically used in combo with chloroquine for chemoprophylaxis
active against erythrocytic schizonts of all four malaria spp |
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pyrimethamine & proguanil - pharmacokinetics
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pyrimethamine t1/2 = 3.5d
proguanil t1/2 = 16h |
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pyrimethamine & proguanil - MoA
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inhibition of plasmodial dihydrofolate reductase
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antibiotics used in malaria
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tetracycline, doxycycline, clindamycin, azithromycin
**effective against erythrocytic schizonts of all 4 spp |
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malaria prophylaxis
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chloroquinolone.
**resistance = atovaquone +proguanil if pregnant, MQ |
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malaria treatment
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CQ
resistance - atovaquone + proguanil or quinidine/quinine + doxy severe - quinidine/quinine +doxy or artesunate |
