Anti-parasitics Flashcards
what is the objective of chemotherapeutic drugs?
to level the playing field so that the body’s own defense mechanisms will have an opportunity to prevail against the invaders
what is a parasite?
an organism that lives in or on a host organism and gets its food from or at the expense of its host
3 main classes of parasites?
protozoa
helminths
ectoparasites
what can Trypanosoma cruzi cause? two drugs that can be used to tx that are -cidal?
chagas disease
can cause cardiomyopathies in chronic cases
azoles and nitros
what can Toxocariasis cause?
blindness, esp in children
where can one pick up toxoplasmosis?
from cat feces and from infected meat/tissues
when would you tx toxoplasmosis? how do you tx/
in immunocompromised individuals
tx with selected antimalarial and antibiotic drugs
what is the most common non-viral STD in the US? MC tx?
trichomoniasis (gonorrhea)
MC tx: metronidazole
5 drugs to tx malaria?
choroquine
quinine
primaquine
artimisinins (artesunate, artemether)
2 drugs to tx amebiasis?
metronidazole
tinidazole
cellular make-up of protozoa?
microscopic, one-celled organisms that can be free-living or parasitic in nature
if live in GI then will be be transmitted fecal-oral route
if live in blood or tissue then will be transmitted via anthropod vector
4 groups of protozoa?
sarcodina
mastigophora
ciliophora
sporozoa
tx of malarial protozoa?
chloroquine
tx of amebiasis and other protozoa?
metronidazole
tx of helminths?
mebendazol
tx of ectoparasites?
ivermectin
category of chloroquine? MOA?
category: anti-protozoal
MOA: damages parasitic DNA, damages membrane of RBC that is infected, can also inactivate enzyme of plasmodium that normally polymerizes the heme that is released as the parasite digests the host Hgb
predicted actions of chloroquine?
prophylaxis or acute tx of malaria dt P. falciparum
SEs of chloroquine?
GI upset, h/a, pruritis, can cause retinal damage, use cautiously in pts w/hepatic dysfxn, can cause severe hemolysis in pts w/G6PD deficiency
4 distinguishing characteristics of chloroquine?
PO
rapidly absorbed
may allow for cure in less than 1 wk
resistance is now reported in some parts of the world
category of metronidazole/flagyl? MOA?
category: antibiotic/antiprotozoal
MOA: binds to protozoan or anaerobic bacterial DNA= no more cell division
4 distinguishing characteristics of metronidazole/flagyl?
azole compound
inhibits aldehyde dehydrogenase in liver
highly lipid soluble
metallic taste
predicted actions of metronidazole/flagyl?
absorbed via all routes distributed to all tissues use caution in pts w/hepatic dysfxn as can cause severe hemolysis in pts w/G6PD deficiency c/i with EtOH CANNOT tx yeast and tinea overgrowth
category of mebendazole/vermox? MOA?
category: antihelmintic (most commonly used)
MOA: microtubule destruction
distinguishing characteristics of mebendazole/vermox?
chewable tablet available
few adverse SEs
excreted, unchanged in feces
avoid during PG
mebendazole/vermox is effective in treating what?
helminths: pinworms, roundworms, whipworms, hookworms
category of ivermectin? MOA?
category: antiparasitic (helminths and ectoparasites)
MOA: intensify release of GABA transmission
distinguishing characteristic of ivermectin?
administered orally
predicted actions of ivermectin?
avoid w/benzodiazepines and barbiturates
cidal to helminths and arthropods
systemic distribution to parasites
avoid during PG
category of pyrethrins? MOA?
category: antiparasitic, insecticide, insect repellant
MOA: sustain open Na channels in insects
distinguishing characteristics of pyrethrins?
produced by chrysanthemum flower
biodegradable
predictable actions of pyrethrins?
repeated and extended nerve d/c in insects
insect seizure before death
replaced irreversible cholinesterase inhibitors
category of arteisinin (qinghaosu)? MOA?
category: antiparasitic, antiprotozoal
MOA: schizonticide in all malarial forms, possibly via free radical formation
distinguishing characteristics of arteisinin?
derivative of ancient chinese herbal medicine
relatively recent commercial use
predicted actions of arteisinin?
limited resistance
emerging as first line drug over quinine derivatives
