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Pharm 3 ABX
ABX
Question | Answer |
---|---|
Aminoglycosides MOA | Irreversiblely inhibits PRO synthesis by binding to 30S subunit--> misreads mRNA |
Aminoglycosides: cidal or static? | cidal |
Tetracyclines MOA | Bind to 30S subunit, block binding of aminoacyl tRNA to acceptor site (A) on the mRNA-ribosome complex-->AA can't be added to the growing peptide. |
Tetracyclines: cidal or static? | static |
Spectinomycin | inhibits PRO synthesis by binding to 30S subunit---> doesn't misread like AG's do) |
Spectinomycin: cidal or static? | static |
Macrolides | PRO synthesis inhibitor, reversibly binds to site on 50S subunit and inhibits translocations step where tRNA moves from A site to P site |
Macrolides: static or cidal? | static |
Lincosamides | reversibly binds to 50S, like macrolides |
Lincosamides: static or cidal? | static |
Chloramphenicol | PRO synthesis inh. REVERSIBLY binds to 50S, inh. transpeptidation by inh. peptidyl transferase. Prevents binding of AA end of aminoacyl tRNA to acceptor site on 50S subunit |
Chloramphenicol: static or cidal? | Static |
Oxazolidione (Linezolid) | inh PRO. Binds to 23S of RNA of the 50S subunit-->nonfunctional 70S initiation complex which is an essential step in the translation process |
Oxazolidione: what is unique? | unique MOA, doesn't show cross resistance to other abx. |
Streptogramins | bind to 23S RNA or 50S subunit; do not induce the methyl's enzyme (not subject to MLS resistance) |
PCN | same as other B-lactam abx. Distrupts synthesis of peptidoglycan layer of bacterial cell wall. inhibits final stage of cell wall synthesis (cross linking) structural analog of d-ala d-ala |
cephalosporins: cidal/static | cidal |
PCN: cidal/static? | cidal |
cephalosporins | disrupts synthesis of peptidoglycan layer of bacterial cell wall |
carbapenems | inhibition of cell wall synthesis |
carbapenems: cidal or static? | cidal |
monobactam | disrupts synthesis of peptidoglycan layer of bacterial cell wall |
monobactam: cidal/static? | cidal |
vancomycin | inhibits cell wall synthesis by irreversibly binding to the pair of d-ala molecules of cell wall precursor units |
vanco: cidal/static | static |
bacitracin | inhibits cell wall synthesis by binding to precursor of cell wall and forming unusable complex; acts 1 step before the one inhibited by vanco |
fosfomycin | inhibits very early stage of cell wall synthesis. inh. enolpyruvyl transferase, irreversibly blocks condensation of UDP-N-acyely glycosamine w/p-enolyruvate; |
fosfomycin | inhibits bacterial adherence to uroepithelial cells (enzymes needed for synthesis of peptidoglycan layer) |
fosfomycin: static/cidal? | cidal |
sulfonamides | PABA anolog, competitively inh DHPS which is required for folic acid synthesis; it only affects bacteria that synthesize their own folic acid |
metronidazole | nitro group is activated in anaerobic organisms to chemically reactivate intermediates that react with DNA. |
metronidazole | increased degradation of existing DNA, altered DNA helical structure, increased strand breaks, inhib of DNA |
metronidazole cidal or static | cidal |
polymixins | surface active agents that disrupt osmotic properties and transport mech of cell membranes in gram neg bacterial only |
polymixins | binds and inactivates endotoxins |
mupirocin (bactroban) | reversibly binds to bacterial isoleucyl-tRNA synthase and blocks PRO synthesis |
fluoroquinolones | inhibits DNA gyrase which is a topoisomerase responsible for breaking and rejoining DNA strands necessary for dNA replication |
fluoroquinolones: cidal/static | cidal |
ketolides | binds to 50S, same as macro lids |
ketek | black box warning: choninergic antagonist; careful in MG and NMBD |
clindamycin | can cause NMB pre and post junctional |
polymyxin B and E | skeletal weaknes; sig potentiation of NMB |
aminoglycosides: inhibit what | release of ach and decreases sensitivity at junction to ach, can potentiate NMBD and lidocaine |