Pharm: Antiparasitics Flashcards
During treatment for malaria a patient begins to experience abdominal cramps, headache, vertigo, BOV and tinnitus. What drug was he most probably given?
Quinine
When quinine cannot be given because of vomiting what stereoisomer can be given IV?
Quinidine
What enzyme does pyrimethamine and cycoguanil block to stop plasmodium?
Protozoan Dihydrofolate Reductase
This quinine derivative appears to disrupt the mitochondrial electron transport in Protozoa. It is a component of ___, used in ___.
Atovaquone, a component of malarone (along with proguanil), which is effective for chemoprophylaxis and treatment of falciparum malaria.
The only anti-malarial drugs reliably effective against quinine-resistant chains
Artemisinins
Malarone is composed of which two drugs. Fansidar? Coartem?
Malarone is a fixed combination of proguanil with atovaquone.
Fansidar is a fixed combination of pyrimethamine and sulfadoxine.
Coartem is a combination of lumefantrine and artemether
What are the luminal amebicides?
DIP
Dilozanide furoate
Iodoquinol
Paromomycin
What is the MOA of emetines?
Tissue amebicides which inhibit protein synthesis by blocking ribosomal movement along mRNA
What is the mechanism of action of the DOC for Chagas’ disease?
Nifurtimox, inhibits trypanothione reductase
An aminoglycoside used as a luminal amebicide
Paromomycin
MOA of pentamidine? Indications?
Unknown but may involve:
- Inhibition of glycolysis
- Interference with nucleic acid metabolism
Second line drug for toxoplasmosis (1st line is sulfa-pyridoxamine)
TMP-SMZ prophylaxis in AIDS is started when CD4 count falls below ____. It is prophylactic against:
200 cells/uL
PCP pneumonia
Toxoplasmosis
Isospora belli infection
What are the mechanism of actions of drugs used for P vivax and P ovals infections?
Chloroquine heme accumulation AND
Primaquine free radical formation
What is the mechanism of action the drugs used for uncomplicated infections with chloroquine resistant P. falciparum?
Quinine prevents DNA separation AND
Doxycyline binds to 30s ribosome
What is the mechanism of action of Malarone?
Cygoguanil for dihydrofolate reductase inhibition
AND
Atovaquone disrupts mitochondrial electron transport
What are the three tissue amoebicides?
Chloroquine, metronidazole/tinidazole, emetine
Drug of choice for African sleeping sickness? MOA?
Melasoprol
Inhibits enzyme sulfhydryl groups
What is the drug of choice for toxoplasma infection?
Pyrimethamine plus sulfadiazine with folinic acid if encephalitis long term trreatmet
What is the MOA for the DOC for leishmaniasis?
Sodium stibogluconate, inhibition of glycolysis and nucleic acid metabolism.
Name symptoms of cinchonism, a known adverse effect of quinines.
GI distress Vertigo Headache Blurred vision Tinnitus
At high doses what are the 2 important AE’s of chloroquine?
Auditory and renal dysfunction
What are the prophylactic regimens in:
- Regions without falciparum resistance
- Regions with chloroquine-resistant falciparum
- Regions with MDR-falciparum
- Chloroquine
- Mefloquine
- Doxycycline / malarone
What is the MOA of the DOC for Ascariasis?
Albendazole or Mebendazole: Inhibition of microtubule formation.
Albendazole is the primary drug for:
Ascariasis
Hookworm
Pinworm
Whipworm
Diethylcarbamazine is the drug of choice in infections caused by:
Wuchereria bancrofti
Brugia malayi
Loa loa (eye worm disease)
Ivermectin is the drug of choice for:
Strongyloidiasis
Cutaneous larva migrans
Onchocerciasis
This drug which stimulates nicotinic receptors at the neuromuscular junction is the drug of choice for infections caused by:
Pyrantel pamoate for hookworm and roundworm infections
What is the DOC for all trematodes except Fasciola hepatica? What is it’s MOA?
Increase in membrane permeability causing marked contraction then paralysis.
What is the only Cestoda that does not have Praziquantel as DOC?
Echinococcus granulosus uses Albendazole.
What is the MOA of niclosamide?
Uncoupling oxidative phosphorylation and activating ATPases.
Praziquantel is contraindicated in:
Ocular cysticercosis
Organophosphate drug converted by the body to the dichlorvos, which acts on S. haematobium
Metrifonate
This drug is effectively solely in S. mansoni infections causing paralysis of the worms.
Oxamniquine
A patient was treated with DEC after being diagnosed with Brugia malayi. He began to experience rashes, fever, ocular damage, and lymphangitis. Why?
Reactions to proteins of dying filariae
What is the MOA of the SOC for Onchocerca volvulus and Strongyloides stercoralis?
Intensifies GABA transmission in the worms. Resulting in paralysis.
In contrast to the MOA of ivermectin how does Pyrantel pamoate cause paralysis of the worms?
Stimulates nicotinic receptors resulting in depolarization induced paralysis.
What is the treatment for T. brucei that presents with winter bottom sign only and kerandel sign only?
Suramin
What is the toxicity associated with mebendazole at high doses?
Agranulocytopenia and alopecia
What should be avoided when taking niclosamide?
Ethanol for 24 to 48 hours
What is the contraindication to pyrantel pamoate?
Hepatic dysfuncition?
What intensifies GABA in nematodes?
Ivermectin
Fever, dizziness, rashes, pruritus, tachycardia, hypotension, joint pain and muscle pain after DEC treatment?
Mazotti reaction
What accumulates when Chloroquine acts on Plasmodium?
Heme
