Medchem of antimalarial and antiparasitic drugs Flashcards
How are lice transmitted?
Through direct contact
What population is most likely to be infected by lice?
Children 3-11 yo
How are pinworms transmitted?
Fecal-oral transmission
What populations are most likely to be infected by pinworms?
- School-age children 5-10 yo
- Institutionalized persons
- Househould members or caretakers
What is the most common symptom of a lice infection?
Itching
What are symptoms of a pinworm infection?
- Compromised nutritional status
- Reduced cognitive processes
- Tissue reactions
- Intestinal obstruction or rectal prolapse
What are the symptoms of pinworm infection in pre-school and school-aged children?
- Stunted growth
- Diminished physical fitness
- Impaired memory and cognition leading to educational deficits
What are the treatment options for lice?
- Spinosad
- Perethrins
What is the MoA of spinosad?
- Nicotinic Ach receptor agonist
- Rapid excitation of insect nervous system causes death
What is the MoA of perethrins?
Nerve membrane sodium channel toxins
What are the treatment options for pinworms?
- Benzimidazoles: mebendazole, albendazole
- Pyrantel pamoate
What is the MoA of benzimidazoles?
Inhibits formation of microtubules which inhibits cell division
What is the MoA of pyrantel pamoate?
- It’s a depolarizing neuromuscular blocking agent
- Causes release of Ach and inhibition of cholinesterase
- Worms are paralyzed and expelled
What insect is responsible for transmitting malaria?
Mosquitoes
What are the two organisms that cause the vast majority of malaria infections? And which one of the two causes relapses?
- Plasmodium falciprum
- Plasmodium vivax: relapsing malaria
Describe the metabolism of hemoglobin by malaria parasites.
- Malaria parasites ingest hemoglobin from host cell
- Degrade hemoglobin to AAs and free heme in food vacuole
- Free heme is toxic, so it’s polymerized into hemozoin, which is nontoxic
What drugs are in the 4-aminoquinolones class?
- Chloroquine/ hydroxycholoroquine
- Quinine
How do aminoquinolones like chloroquine stop the hemoglobin metabolism by malaria parasites?
Accumulates in food vacuole and inhibits heme polymerization
What is the MoA of artemisinin?
- Activated via heme-iron in food vacuole
- Forms free radicals after activation
- Triggers unfolded protein response
- Inhibits translation, proteasome, mitochondria
What is the second proposed MoA of artemisinin?
May inhibit phosphatidylinositol-3-kinase (PfPI3K)
What is the key functional group in artemisinin?
What is the MoA of primaquine?
Produces H2O2 that kills plasmodium parasites
What is the MoA of doxycycline?
Binds to 30S ribosomal subunit and inhibits protein synthesis
What is the drug of choice for hyponozoite stage of P. vivax?
Primaquine (in combination with chloroquine)
