Antiparasitic Drugs 1 Flashcards
MoA of Albendazole?
inhibits microtubule assembly
MoA of Diethylcarbamazine?
immobilizes microfilariae by unknown mechanism, renders them more susceptible to host defenses
MoA of Ivermectin?
intensifies GABA neurotransmission in nematodes and causes immobilization, facilitating removal by RES
(selective toxicity b/c GABA is only in CNS in humans and ivermectin doesn’t cross BBB)
MoA of Mebendazole?
inhibiting microtubule synthesis and glucose uptake in nematodes
MoA of Piperazine?
paralyzes ascaris by acting as agonist at GABA receptors.
paralyzes roundworms are expelled live by normal peristalsis
MoA of Pyrantel pamoate?
stimulates nicotinic receptors present at NMJ of nematodes. contraction of muscles occurs, followed by depolarization-induced paralysis.
no actions on flukes or tapeworms
MoA of Thiobendazole?
structural congener of mebendazole. inhibits microtubule assembly
MoA of Praziquantel?
increases membrane permeability to Ca++
marked contraction initially and then paralysis of trematode and cestode muscles. this is followed by vacuolization and parasite death
MoA of Bithionol?
unknown.
codrug of choice (w/ triclabendazole) for treatment of fascioliasis and alternative for paragonimiasis
MoA of Metrifonate?
organophosphate prodrug. converted in the body to the cholinesterase inhibitor dichlorvos.
the active metabolite acts only on Schistosoma haematobium.
MoA of Oxamniquine?
causes paralysis of Schistosoma mansoni by unknown mechanism.
MoA of Niclosamide?
uncouples oxidative phosphorylation or possibly activates ATPases
MoA of Chloroquine?
accumulates in food vacuole of plasmodia and prevents polymerization of the hemoglobin breakdown product heme into hemozoin
intracellular accumulation of heme is toxic to the parasite
MoA of quinine?
complexes w/ dsDNA to prevent strand separation, resulting in block of DNA replication and transcription to RNA.
MoA of Mefloquine?
unknown
MoA of Primaquine?
quinolone-quinone metabolites that are electron-transferring redox compounds that also act as cellular oxidants.
MoA of Proguanil?
sulfonamide. blocks folic acid synthesis…
proguanil is activated to cycloguanil which is selective inhibitor of dihydrofolate reductase
Antimalarial drugs with QT prolongation?
halofantrine
MoA of Artemisinins?
metabolized in food vacuole to form free radicals
Prevent malaria in travelers?
Chloroquine weekly is doc in places w/o resistance
Mefloquine weekly in places w/ resistance
in places w/ MDR malaria, use Malarone (proguanil + atovaquone)
MoA of emetines?
block ribosomal movement along messenger RNA, thus inhibiting ameobal protein synthesis
MoA of melarsoprol?
inhibits enzyme sulfhydryl groups
drug of choice in African trypanosomiasis
DoC in African sleeping sickness?
Melarsoprol
inhibits enzyme sulfhydryl groups
DoC in American trypanosomiasis?
Nifurtimox
inhibits parasite-unique enzyme trypanothione reductase
MoA of Nifurtimox?
inhibits parasite-unique enzyme trypanothione reductase
drug of choice in America trypanosomiasis
Drug of choice for Leishmaniasis?
sodium stibogluconate
appears to kill parasite by inhibition of glycolysis or effects on nucleic acid metabolism
MoA of Paromomycin?
aminoglycoside antibiotic
(30S subunit -> inhibit protein synthesis)
(used as a luminal amebicide)
MoA of Eflornithine?
suicidal substrate of ornithine decarboxylase
effective in some forms of African trypanosomiasis
Antimalarial that can precipitate porphyria attacks?
chloroquine
What is cinchonism?
caused by quinine/quinidine:
tinnitus, vertigo, h/a, GI distress, blurred vission
severe overdose can result in cardiotoxicity (torsades?)
Antimalarial that can cause Blackwater Fever?
quinine
Blackwater fever is a rare intravascular hemolysis
Antimalarial that can cause methemoglobinemia?
Primaquine
also causes hemolysis in G6PD deficiency
