Flashcards in Antihelminthic Drugs Deck (62):
What is Taenia saginata?
What are the flatworms?
T. saginata, T. solium, Diphyllobothrium latum, Hymenolepis nana, Schistosoma hematobium, S. mansoni, S. japonicum
What is T. solium?
What is Diphyllobothrium latum?
How do you get T. saginata?
Eating undercooked meat
How do you get T. solium?
Eating undercooked pork
How do you get D. latum?
Eating undercooked fish
What is the largest tapeworm?
What is the main nutrient that D. latum robs from the host?
What is the lifecycle of T. solium and saginata?
1. Animals become infected by eating eggs or proglottids 2. Oncospheres hatch and penetrate intestinal walls and circulate to the muscles 3. Oncospheres develop into cysticerci in muscle 4. Cysticerci eaten by humans 5. Cysticerci grow into worms
What causes cysticercosis?
Autoinfection by T. solium. Same lifecycle as normal, but simply in the human. Cysticerci develop in brain, liver, and other tissues
What is a high risk of T. solium infection?
What is Hymenolepis nana?
What is the most common Tapeworm infection?
How is one infected by H. nana?
Ingesting eggs. Humans can transmit to humans. Children predominatly infected
What are Cestodes?
What are Trematodes?
Flukes or Schistosomes
What does Praziquantel treat?
Cestode and Trematode infestations
How does Praziquantel work?
It disrupts Ca2+ homeostasis, causing muscular contraction followed by spastic paralysis. Worms dislodge and die
What is the drug of choice for all forms of schistosomiasis?
What does Praziquantel not kill?
Eggs of T. solium
What is one of the major risks of taking Praziquantel?
Severe rxn to dying worms
What are the Nematodes?
Necator americanus, Ancylostoma doudenale, Enterobiasis, Ascariasis, Trichuriasis, Trichinella spiralis, Filariasis, Loa loa, Anchocerca volvulus
What are the hookworms?
Necator americanus and Ancylostoma doudenale
How do hookworms infect their host?
Through the skin or oral ingestion
What is the most common worm infection in the US?
What is the infection cycle for Enterobiasis?
1. Female lays eggs on anus at night, 2. Eggs grabbed by fingers, 3. Eggs ingested
What is the most common worm infection in the world?
Where do ascaris reside?
What is the Ascaris lifecycle?
1. Ingested Eggs, 2. Larva hatch in SI, 3. Penetrate intestinal wall transported to lungs, 4. ~10d worms pass through lungs to trachea and are re-swallowed, 5. Return to SI
What infection is common in tourists who vist the subtropics and the S.E. US?
Where do Trichuris live?
What are some of the symptoms of Trichuriasis?
Irritation, Inflammation of colonic mucosa, abdominal pain, diarrhea, distention
How do you get Trichuriasis?
Ingesting eggs in contaminated food/liquids
Where do filaria live?
What organisms cause Filariasis?
Wuchereria bancrofti, Brugia malayi, Brugia timori, Loa Loa, Onchocerca volvulus
How are filaria transmitted?
What do filaria cause?
How is Loa loa transmitted?
How is Onchocerca volvulus transmitted?
What is the worst outcome of Loa loa infection?
Ocular lesions can lead to blindness
What does Onchocerca volvulus cause?
What are the Benzimidazoles?
Mebendazole, Thiabendazole, Albendazole
What is the MOA of the Benzimidazoles?
Bind to tubulin. Microtubules grow from the (+) end and benzimidazoles cap the microtubules, The microtubules then shorten on the (-) end
How can you increase the absorption of benzimidazoles?
Eating a fatty meal
How do you specify P.O requirements when treating luminal parasites w/ benzimidazoles?
Take on empty stomach
How do you specify P.O. requirement when taking benzimidazoles for tissue infections?
Take w/ a fatty meal
Which benzimidazole forms an active metabolite on hepatic metabolism?
Albendazole is converted to an active sulfoxide form
Which benzimidazole is more toxic?
Thiabendazole; this makes it no longer preferred
What is the drug of choice for cysticercosis?
What is the drug of choice for pinworms, hookworms, ascariasis, trichuriasis, and strongyloidiasis?
What is treated w/ Mebendazole?
Pinworms, hookworms, ascariasis, and trichuriasis
What is Diethylcarbamazine used to treat?
Filariasis and loiasis
What is the Mazzotti rxn?
Severe immune response to dying worms
What does Ivermectin treat?
Strongyloidiasis and Onchocerciasis
What is the MOA for Ivermectin?
1. Paralyzes microfilariae, 2. Intensifies GABA-mediated transmission of signals in peripheral nerves, 3. Allows host cytotoxic cells to adhere
Does Ivermectin kill adult worms?
No, it only blocks progeny release
Why are many herding breeds sensitive to Ivermectin?
They lack the P-glycoprotein transporter (MDR1 gene) in the brain
What is a broad spectrum antihelminth?
What can Pyrantel pamoate not treat?
migratory stages or ova of helminths
What is the MOA of Pyrantel Pamoate?
Neuromuscular blocking agent; Causes release of ACh and inhibits cholinesterase. This paralyzes worms