Tx for Select GI Infections Flashcards
What is the agent of choice for
Tapeworm- ADULT forms: Diphyllobothrium latum & Taenia Spp (including T. solium, EXCEPT cystercosis specific)
Praziquantel
(boards: D. latum - Vit B12 deficiency- megoblastic anemia
T. solium: intestinal tapeworm)
What is the MOA of Ivermectin
what is used for?
Binds selectively (high affinity) to Glu-gated Cl- ion channels
induce hyperpolarization resulting in tonic paralysis of the worms’ Ns/Ms –> immobilization & death
(use = strongyloides stercoralis)
What is the agent of choice for
Roundworm: Ascaris lumbricoides
Albendazole (Mebendazole)
(boards: obstruction of ileocecal valve, biliary obstruction, intestinal perforation, migrated from nose/mouth)
What is the MOA for Nitazoxanide
what is it used for?
interfere w/ pyruvate: ferredoxin oxidoreducatase (PFOR) enzyme-dependent e- transfer reaction (essential for anaerobic energy metabolism)
(cryptosporidium parvum, giardia labmlia, entamoeba histolytica)
how often should you monitor levels of VAN after prescribing for C. diff
YOU DONT HAVE TO! :) *pimp question*
VAN usually given by IV for MRSA and have to monitor to prevent ear & kidney toxicity
BUT orally (given in C. diff) does not get abs-ed in a similar fashion
What is the agent of choice for
Tapeworm - LARVAL form: T. solium cysticercosis specific
Albendazole
(boards: cystic CNS lesions, seizures)
What is the MOA of Pyrantel Pamoate
what is it used for?
depol NM blocker – opens non-selective cation channels and induce persistent activation of nAch receptors –> increase release of Ach
inhibit cholinesterase –> spastic paralysis of parasite
(enterobius vermicularis, ascaris lumbricoides, ancylostoma spp, trichinella spiralis, adult form)
What is the MOA and use of Paromomycin
works similar to other aminoglycosides on 30S subunit
(entamoeba histolytica, diphyllobothrium latum, echinococcus granulosus, taenia spp, schistosoma spp)
What is the agent of choice for
Shigella spp
Cipro
Azithromycin
If a pt was recently treated for C. diff with metronidazole, now presents again with C. diff. What medication will you treat them with?
VAN
What is the agent of choice for Entamoeba histolytica
Metronidazole followed by paromomycin
(boards: Sxs = bloody diarrhea, liver abscess (anchovy paste exudate), RUQ pain, histology of colon Bx = flask shaped uclers)
what are the classification of drugs:
Vancomycin
Ciprofloxacin
Fidaxomicin & Azithromycin
Vancomycin: glycopeptide
Ciprofloxacin: Fluoroquinolone
Fidaxomicin & Azithromycin: Macrolide
What is the recommended treatment for C. Diff
Vancomyosin Oral ONLY!
previously metronidazole was used alot but less now bc of resistance
What is the agent of choice for
Giardia Spp
Metronidazole (Tinidazole)
(boards: bloating, flatulence, foul smelling fatty diarrhea (hikers/campers))
What is the MOA for Benzimidazole
inhibit microtubule polymerization via beta-tubulin binding –> reduced glucose transport
inhibit mitochondrial fumarate reductase –> immbolization & death
What is the agent of choice for
Pinworm: Enterobius vermicularis
Mebendazole (Albendazole)
(boards: anal itchy - seeing egg via tape test)
What is the agent of choice for
Tapeworm: LARVAL form: Echinococcus granulosus
Albendazole PLUS Praziquantel
(boards: hydatid cysts - eggshell calcification in liver; cyst rupture can cause anaphylaxis)
What is the recommended treatment for C.diff is the pt presents w/ hypotension/shock, ileus, megacolon
VAN & metronidazole
What is the MOA and use of atovaquone-proguanil
Atovaquone: selectively interfere w/ mitochondrial e- transport & ATP/pyr biosynthesis
Proguanil: selectively (-) bifxnal dihydrofolate reductase-thymidylate synthetase enzyme of plasmodia –> (-) DNA synthesis & cause depletion of folate cofactors
(plasmodium falciparum)
What is the agent of choice for
Cryptosporidium spp
Nitazoxanide
(boards: severe diarrhea in AIDS, mild dz-watery diarrhea in immunocompetent hosts)
What is the agent of choice for
Hookworms: Ancylostoma spp. & Necator americanus
Albendazole (Mebendazole)
(boards presentation: microcytic anemia; cutaneous larva migrans = itchy, serpiginous rash from walking barefoot on beach)
What is the MOA for Praziquantel?
what is it used for?
increased cell membrane permeability –> loss of intracell Ca2+ –> massive contractions ending in paralysis of Ms
disintegration of schistosome tegument followed by attachment of phagocytes leading to death
(schistosoma spp, echinococcus granulosus, taenia spp, diphyllobothrium latum)
What is the agent of choice for
Schistosomiasis spp.
Praziquantel (+ steroids for neurological dz)
(boards: HSM, fibrosis, inflamm, portal HTN; chronic infection –> bladder SCC, painless hematuria and pul HTN)
What are the drugs under the miscellaneous category for helminths
ivermectin
nitazoxanide
praziquantel
pyrantel pamoate
What is the agent of choice for
Campylobacter jejuni
Cirpo
Azithromycin (esp if allergic to cipro)
(boards: bloody diarrhea (esp kids), consumption of undercooked contaminated poultry/meat, unpastuerized milk)
What is the agent of choice for
Salmonella Spp
Cipro
Azithromycin
If a patient was previously treated for C. diff and they have a reoccurance of C. diff. What do you prescribe?
Fidaxomicin (FDX)
What is the agent of choice for
Threadworm: Strongyloides stercoralis
Ivermectin
(boards: GI, pul, skin symptoms; hyperinfection syndrome caused by autoinfection)
What medications are used as GI focused anti-protozoals
Paromomycin (aminocylgoside)
Metronidazole & Tinidazole
What is the agent of choice for
Trichinella spp.
Albendazole (Mebendazole) (+ steroids for severe dz)
(boards: encyst in striated muscle, myositis; trichinosis- fever, vomiting, nausea, periorbital edema, myalgia)
What is the agent of choice for
Whipworm: Trichuris trichiura
Mebendazole (Albendazole)
(boards: often asymp, loose stools, anemia, rectal prolapse in kids)
What are the MC drug used for helminths?
Benzimidazoles
Albendazole
Mebendazole
Thiabendazole (skin only)
What is the agent of choice for
Cyclospora cayetanensis
TMP-SMZ (bactrim)
Cipro -for sulfa allergic pts
What is the MOA and uses of Metronidazole & Tinidazole
= prodrugs activated by e- transfer process creating nitro-radicals which disrupts DNA –> kill the organism
(entamoeba histolytica, giardia lamblia, c. diff)
