Antiparasitic Flashcards
3 targets for antiparasitic chemotherapy
Enzymes or processes found only in the parasite(PFOR, folate synthesis). Enzymes or processes found in both the host and parasite but indispensable only in the parasite (purine salvage pathways). Common biochemical functions found in both parasite and host but w/ different pharmacologic properties (DHFR; microtubule disrupters)
How does metronidazole work
Metronidazole is prodrug, reduced by PFOR into active form.
What 3 organisms cause opportunistic parasitic infections of AIDS patients and the immunocompromised
Cryptosporidium parvum, pneumocystis jirovecci, toxoplasma gondii
What drug treats cryptosporidiosis
Nitrazoxanide. Shuts down pyruvate:ferredoxin oxidoreductase (PFOR)
Drug for treating toxoplasmosis
Pyrimethamine sulfadiazine
Drug to treat pneymocystis jirovecci
Trimethoprim-Sulfamethoxazole(TMP-SMX)
Side effects of quinine
Quinine has poorest therapeutic:toxic ratio of all antimalarial drugs. Cinchonism, hypoglycemia
Mefloquine
Well tolerated, used for prophylaxis and treatment. Toxicity-some reports demonstrate severe neuropsychiatric reaction in 0.5% of pts receiving mefloquine for treatment. Treatment dosage greater than prophylactic doses
What is only drug available that has activity against the liver (hypnozoite) forms of P vivax and P ovale?
Primaquine
Major toxicity of primaquine
RBC lysis in persons with G6PD. Screen before administration
Name the 3 benzimidazoles
albendazole, mebendazole, thiabendazole.
What benzimidazole has the greatest toxicity
Thiabendazole bc most efficiently absorbed
How does ivermectin work
causes muscle paralysis in parasite. Good tissue penetration, so can target worms throughout the body
Ivermectin is drug of choice for what diseases
strongyloidiasis, O volvulus (river blindness), L loa (eye worm) and filarial worms
Treat pinworm with what
Pyrantel pamoate
