Sulfonamides, trimethoprim, fluoroquninolones, metronidazole Flashcards Preview

Boards microbio and biochem > Sulfonamides, trimethoprim, fluoroquninolones, metronidazole > Flashcards

Flashcards in Sulfonamides, trimethoprim, fluoroquninolones, metronidazole Deck (12):

sulfonamides: mechanism and resistance. cidal/static

sulfonamides are PABA analogues. they inhibit dihydropteroate synthesis, which is an enzyme needed for folate synthesis. bacteriostatic.
resistance develops when the enzyme is altered, decr. uptake, or incr. PABA synthesis


sulfonamide use

gram positive, gram negative, nocardia, chlamydia. SMX or triple sulfides for simple UTI


sulfonamide toxicity

hypersensitivity, hemolysis if G6PD deficient, nephrotoxicity (tubulointerstitial nephritis), photosensitivity, kernicterus, displace other drugs, like warfarin, from albumin


trimethoprim mechanism

inhibits folate synthesis by inhibiting dihydrofolate reductase. bacteriostatic.


trimethoprim use

used in combo with sulfonamides. causes a block of folate synthesis. used in combination for UTIs, shigella, slamonella, pneumocystis jirovecii treatment and prophylaxis, and toxoplasmosis prophylaxis


toxicity of trimethoprim

megaloblastic anemia, leukopenia, granulocytopenia.


fluoroquniolones mechanism and special considerations. cidal/static. resistance

inhibit DNA gyrase and topoisomerase IV. cidal. must not take with antacids. resistance via chromosome-encoded mutation in DNA gyrase, plasmid mediated resistance, or efflux pumps


fluoroquinolones use

gram negative rods of urinary and GI tracts (incl. some pseudomonas), Neisseria, some gram positive organisms


toxicity to fluoroquinolones

GI upsett, superinfections, rashes, headache, dizziness. tendonitis, tendon rupture, myalgias. contraindicated in pregnancy, nursing, and childhood because of possible cartilage damage. some cause prolonged QT intervals


metronidazole mechanism, cidal/static

free radical formation in the bacterial cell that damages DNA. bactericidal and antiprotozoal.


use of metronidazole

treats giardia, entamoeba, trichomonas, gardnerella vaginals, anaerobes. use with PPI and chlarithromycin for treatment of H. pylori


metronidazole toxicity

disulfram-like rxn; metallic taste