2.10 GI Pharm: Parasites + Bugs Flashcards
Reduced by pyruvate:ferredoxin oxidoreductase to active free radicals that attack DNA and other macromolecules in anaerobic organisms?
Metronidazole / Tinidazole
Effective against Entamoeba histolytica but could cause a metallics taste in mouth?
Metronidazole / Tinidazole
Who should metronidazole and Tinidazole be avoided in?
Disulfiram-like effects (avoid alcohol during and 3 days after treatment).
Avoid in pregnancy and breastfeeding.
Aminoglycoside antibiotic interfering with protein synthesis.
Paromomycin
Poorly absorbed so good for intestinal infections especially eradication of E. histolytica trophozoites and intestinal carriage?
Paromomycin
What drugs are used to treat amebiasis?
Metronidazole, Tinidazole, Paromomycin
Interferes with pyruvate:ferredoxin oxidoreductase enzyme-dependent electron transfer in anaerobic metabolism.
NItazoxanide
What is effective for Giardia lamblia and cryptosporidium?
Nitazoxanide
How is NItazoxanide ADME and ADSE?
Oral (active @ liver = tizoxanide)
GI and CNS side effects
Unclear; inhibits oxidative phosphorylation and RNA/DNA synthesis.
Pentamidine
Pancreatic toxicity, hypoglycemia, hypotension, renal insufficiency.
Pentamidine
Used for Early-stage Trypanosoma brucei gambiense
Pentamidine
Pentamidine ADME?
Parenteral; large distribution, minimal CNS penetration, long half-life (~12 days).
Inhibits ornithine decarboxylase, blocking polyamine production needed for DNA/RNA synthesis.
Eflornithine
IV only; effective for T. brucei gambiense (late stage)
Eflornithine
ADSE for Eflornithine?
GI effects, thrombocytopenia, anemia, leukopenia, seizures
Produces free radicals, binding to DNA with Oral, rapid absorption; excreted primarily via kidneys
Benznidazole
ADSE Benzinidazole ?
Rash (manage with corticosteroids), peripheral neuropathy, rare bone marrow suppression, disulfiram-like effects (avoid alcohol)
What is used to treat Trypanosoma cruzi infections (Chagas)?
Benznidazole
Inhibits folate metabolism enzymes synergistically (dihydropteroate synthase and DHFR).
TMP-SMX
Hypersensitivity, crystalluria, GI effects, megaloblastic anemia in folate-deficient patients.
TMP-SMX
Rapid absorption; metabolized in the liver; excreted via urine and used to treat Cyclospora cayetanensis?
TMP-SMX
Inhibits dihydrofolate reductase, blocking tetrahydrofolate formation
Pyrimethamine + Sulfadiazine
What are the ADSE of Pyrimethamine + Sulfadiazine and who should you not use it for?
Hypersensitivity, megaloblastic anemia, risk in G6PD or folate-deficient patients.
Used to treat Toxoplasma gondii and Oral; better tolerated with food.
Pyrimethamine + Sulfadiazine
Inhibits protein synthesis (macrolide).
Spiramycin
Oral, concentrates in placenta with GI effects, QT prolongation, dermatologic
Spiramycin
Spiramycin is used to treat what? (And who?)
Toxoplasmosis in pregnancy
Binds glutamate-gated chloride channels, causing paralysis and death
Ivermectin
GI upset, rash, dizziness, rare severe reactions due to organism death (e.g., fever, bronchospasm). Avoid in patients taking GABA-enhancing drugs.
Ivermectin
What is ivermectin used to treat?
Nematodes and ectoparasites (Onchocerca, Strongyloides, Scabies)
Increases Ca²⁺ permeability, causing paralysis and detachment of worms.
Praziquantel
Praziquantel ADME and ADSE?
ADME: Oral, well absorbed, metabolized by CYP3A4, excreted via kidneys.
Adverse Effects: GI effects, headache, dizziness, exacerbated symptoms with CNS involvement.
What is Praziquantel used to treat?
Trematodes and cestodes (Schistosoma, Taenia)
MOA: Inhibits microtubule formation, depleting glycogen stores and reducing ATP production, leading to energy depletion and death
Albendazole / Mebendazole (Benzimidazoles)
Albendazole / Mebendazole (Benzimidazoles)
ADME and ADSE?
ADME: Poorly absorbed on an empty stomach; better with fatty meals. Extensive first-pass metabolism.
Adverse Effects: Generally safe; occasional GI effects, headache, dizziness.
Uses: Broad-spectrum for nematodes, tissue cestodes, and trematodes?
Albendazole / Mebendazole (Benzimidazoles)
Vancomycin MOA?
Inhibits bacterial cell wall synthesis.
Used to treat C diff. With minimal ADSE if used orally?
Vancomycin
Inhibits RNA polymerase?
Fidaxomicin
Used to treat C diff but can cause mild systemic recitations or GI effects?
Fidaxomicin
What do you use to treat E.coli cases if you need more than supportive?
fluoroquinolones, azithromycin, or TMP-SMX (severe)
What do you use to treat Salmonella, Shigella, Vibrio cholera if supportive care is not enough?
fluoroquinolones, azithromycin, or third-generation cephalosporins**
What do you use to treat campylobacter infections?
Azithromycin or fluoroquinolones for severe or prolonged cases.
What do you use to treat listeria monocytogenes?
Ampicillin (+ gentamicin = synergy)
What do you use to treat yersenia enterocolitica if it is beyond self-limiting illness?
Fluoroquinolones in adults, TMP-SMX in children if needed
