Antiparasitic drugs Flashcards
Most roundworms can be treated with _______, though alternative therapies include pyrantel pamoate, oxantel pamoate, and piperazine.
Benzimidazoles: mebendazole or albendazole
Threadworms are most effectively treated with _______
ivermectin
Th larvae (but not adult stages) of filarial worms can be treated with __________ or diethylcarbamazine
ivermectin
What adverse reactions can be seen when treating heavy worm infections?
massive worm expulsions have been
known to cause rectal prolapses, intestinal blockages, and intense hypersensitivity reactions can be generated in response to worm debris.
Ascaris lumbricoides is almost always treated with:
mebendazole, albendazole, or pyrantel pamoate
What drugs are useful in treatment of mixed infection with hookworms and ascaris?
albendazole or mebendazole
How is hookworm (Necator americanus) treated?
albendazole or mebendazole
What is cutaneous larva migrans?
creeping eruption on skin due to larvae of dog hookworm (Ancylostoma duodenale)
How is cutaneous larva migrans treated?
oral or topical thiabendazole, albendazole
NOT mebendazole
How is whipworm (Trichuris trichiura) treated?
Benzimidazoles or oxantel pamoate
How are threadworms (Strongyloides stercoralis) treated?
ivermectin
How is pinworm (Enterobius vermicularis) treated?
mebendazole, albendazole, pyrantel pamoate
Strict personal hygiene is critical in treatment of ______
pinworm (Enterobius vermicularis)
How is trichinella spiralis treated?
Albendazole and mebendazole effective against early intestinal stage but ineffective against larvae that have migrated to the muscle
How are filarial worms treated?
Ex Wuchereria bancrofti, Brugia malayi
Treated with diethylcarbamazine or ivermectin
In very general terms, describe what drugs are used to treat roundworms vs flatworms
Roundworms: nematodes
- intestinal: mebendazole or albendazole
- filarial: ivermectin
Flatworms: platyhelminths
- tapeworms: praziquantel
- flukes: praziquantel
What is the drug of choice for treatment of onchocerciasis
ivermectin
What is the drug of choice for treatment of loiasis
diethylcarbamazine
With the exceptions of echinococcosis and cysticercosis, ________ is the drug of choice for treating all tapeworm infections
praziquantel
How is echinococcus granulosus treated?
surgical resection and long term albendazole
What is the drug of choice for all schistosomal infections?
Praziquantel
What is the drug of choice for lung, liver, and intestinal flukes?
Praziquantel
What is the mechanism of action of benzimidazoles (albendazole, mebendazole)?
Binds to worm B tubulin which inhibits microtubule polymerization
List toxicities of mebendazole and albendazole
Few systemic toxicities
Not for use in pregnant women
Describe the indications for use of mebendazole
nematode infections including roundworm, hookworm, and whipworm.
List indications for use of albendazole
roundworm, hookworm, pinworm, and whipworm.
zoonotic tapeworm infections (echinococcosis) such as cystic hydatid and alveolar hydatid disease, cysticercosis
It has an advantage over mebendazole in that
very often treatment can be effected with only a single dose of drug.
_____ has low oral bioavailability and remains largely in the gut, which is advantageous for treatment
Mebendazole
Oral bioavailability of ______ is increased with eating a fatty meal
albendazole
Describe the disease caused by the filarial worm Onchocerca volvulus
Cutaneous filariasis
African river blindness
transmitted by black flies, causes lymphatic involvement, dermatitis, blindnesss caused by an endosymbiont (Wolbachia pipientis)
What is the mechanism of action of ivermectin
direct activation of avermectin-sensitive glutamate-gated chloride channels; tonic paralysis of the worm pharyngeal musculature.