Flashcards in Pharm for Parasites/protozoa/C. diff Deck (44):
Drugs used for Nematodes
Drugs used for Cestodes
Drug used for Trematodes
What are the Soil-transmitted helminths
In endemic areas, these drugs are used for treatment of children with helminth infections
-single doses of Albendazole or the older mebendazole
-These are Benzimidazoles
What is the Benzimidazoles that are only used for cutaneous infections
MOA of benzimidazoles
bind to parasite b-tubulin, disrupt microtubule polymerization and microtubule dependent processes like attachment and glucose transport
Which benzimidazole has Poor absorption so low systemic exposure?
Which benzimidazole has modest absorption and has metabolites that can affect tissue dwelling helminths, cysts, and is cleared renally
Albendazone-->Albendazole sulfoxide (active metabolite) --> Albendazole sulfone (inactive and cleared renally)
Benzimidazole used for larval migrans ONLY
Thiabendazole (has systemic toxicity)
Enterobius vermicularis (pinworm . . itchy butt children)
Necator americanus and Ancylostoma duodenale (Hookworms)
Albendazole OR Mebendazole
Trichuris trichuria (Whipworm)
Mebendazole or Albendazole (need 3 day course rather than single dose)
Toxacara (Larval migrans)
Benzimidazoles and pregnancy
Alternative/Adjunct Nematode therapy that is effective against hook, pin, and round worms but NOT Trichuris trichiura
-MOA: binds to N-AChR causing spastic paralysis and depolarization
What is the indication for Pyrantel pamoate therapy
HEAVY Ascaris infection
Pregnancy and Pyrantel Pamoate
Can use but be cautious
Indications for Ivermectin
-Intestinal Strongloidyiasis (thread worm)
-Onchocerciasis (River Blindness)
-Also Lymphatic Filariasis (Wuchereria bancrofti and Brugia malayi)
MOA of Ivermectin
-inactivates Glutamate-gated chloride channels causing hyperpolarization and paralysis
When is Ivermectin contraindicated
-when BBB is disrupated like meningitis and trypanosomiasis
What are the intestinal Cestodes (Tapeworms)
-Taeniasis (pork and beef)
What is the drug of choice for all ADULT form (Taenias and diphyllobothrium) tapeworm infections in US?
Drug of choice for LARVAL forms (Cysticercosis and Echinococcus granulosus/cystic hydatid disease) of tapeworm infections?
What is an adjunct therapy you can add on?
What is a contraindication for Praziquantel therapy
treatment of ocular cysticercosis . . . destruction of organism in the eye may damage the eye
What are the intestinal trematodes/flukes
What would you look for in a stool sample that has schistosomisasis
A spear head coming of the trematode
drug of choice for schistosomiasis
MOA of praziquantel
-interferes with calcium homeostasis and causes flaccid paralysis in adult flukes
-causes antigen within parasite to be exposed to action of host antibodies
Drug list for anti protozoal/antiamebic agents
Metronidazole extensively used to treat what?
What is unique about these organisms is used to target them?
Lack mitochondria and do not rely on pyruvate dehydrogenase
Explain the metabolism of E. histolytic and G. lamblia
Pyruvate -->pyruvate-ferredoxin oxidoreductase (PFOR)-->this activates metronidazole and damages DNA
Drug of choice for E. histolytica?
Adverse effects of Metronidazole/Tinidazole?
-Disulfiram-liek reaction - with intake of acohol -->abdominal distress, vomiting, flushing, headache, alcohol-withdrawal symptoms
-one celled parasite
-can invade liver and form abscess
Symptomatic or invasive colitis is treated with what?
metronidazole followed by luminal amebicide (such as paromomycin, diiodohydroxyquin, or diloxanide furoate) to elminate intraluminal cysts
-aminoglycoside (not orally absorbed)
-Bind to 30S ribosome to disrupt protein synthesis
-drug of choice for colonization of intesting with E. histolytica
-Alternative to metronidazole for E. histolytica infection during PREGNANCY
Flagellated protozoan parasite
Rice paddy fields?
Low CD4 count . . less than 100?
Patient with C. diff . . doesn't respond to metronidazole. give this next ORALLY to treat the diarrhea
Recurrent hospital acquired infectious colitis (C. diff) . . . ICU acquired also