Antibiotics mechs Flashcards by Mani Yavi

Penicillin G; Penicillin V

Complex with PBP, _ transpeptidase: _ cross-linking of peptidoglycans: _ cell wall synthesis

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Oxacillin; Dicloxacillin; Nafcillin (Cloxacillin, Methicillin)

_ transpeptidase _ _ cell wall synthesis; bulky side group to stop _penicillinases

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Ampicillin; Amoxicillin

Hydrophilic amino group _ encanced ability to pass through porins _ confers greater Gram negative activity. _ cell wall synthesis

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Piperacillin; (Ticarcillin; Azlocillin; Carbencillin)

Carboxypenicillin: carboxyl R group allows penetration of porins in G(-) outer memb, _transpeptidase, _cell wall synthesis

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Zosyn (Piperacillin + Tazobactam); Augmentin (Amoxicillin + Clavulanate)

Suicide inhibitor, binds to and inactivates _ _-Lactamase

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Cefazolin; Cephalexin

Bacteriocidal: bind and for complex with PBP, _ transpeptidase: _ cross-linking of peptidoglycans: _ cell wall synthesis; relatively resistant to most (not all) _-Lactamases; Resistance via Transpeptidase mutations, _-Lactamases (esp in G-), Enterococci inherently resistant to cephaosporins

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Cefuroxime (IV); [Cefaclor (PO), Cefuroxime (PO)]

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Ceftazadime (IV); Cefpodoxime (PO); Ceftriaxone (IV)

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Cefepime

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Imipenem (given w/ Cilastin)

Complex with PBP, _ transpeptidase: _ cross-linking of peptidoglycans: _ cell wall synthesis; Highly resistant to _-Lactamases; Broadest Spectrum of Activity of all antibacterials

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Aztreonam

_ transpeptidase: _ cell wall synthesis, unique peptidoglycan targets, resistant to _-Lactamases

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Vancomycin

Binds rapidly and irreversibly to the D-alanyl-D-alanine muramyl pentapeptide of cell wall precursors _ _ polymerization of peptidoglycans

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Daptomycin

Penetrates bacterial cell wall, forming a channel for subsequent leakage of intracellular ions

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Colistin (Polymyxin E); Polymyxin B

Cationic detergents _ Distortion of the membrane lipid structure, _ permeability to polar molecules, via channel

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Ciprofloxacin; (Lomefloxaci, Norfloxacin, Oflaxacin)

Inhibits _DNA gyrase (Topo II) (supercoiling control), and _Topoisomerase IV (untangling daughter Chr), traps enzyme on DNA

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Levofloxacin

Inhibits _DNA gyrase (Topo II) (supercoiling control), and _Topoisomerase IV (untangling daughter Chr), traps enzyme on DNA

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Metronidazole

Reductive bioactivation via ferredoxins (in anaerobic bacteria, some protozoa) cytotoxic free radicals react with & damages DNA, protein, or bacterial membranes

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Rifampin

Inhibits _ RNA Polymerase _ _ mRNA transcription; resistance: RNA poly (_) mutation

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Gentamicin; Tobramycin; (Neomycin, Streptomycin; Amikacin)

O2-dependent uptake (anaerobes innately resistant); binds 30S ribosome _ premature termination, mistranslation (bacteriacidal), _ initiation of translation

Doxycycline; (Tetracycline, Minocycline, Dmeclocycline, Tigecycline)

Reversibly binds 30S Ribosome Subunit: block access of _aminoacyl tRNA to its codon (bacteriostatic); imported via energy-dependent active transport lacking in humans

Clindamycin

Binds 50S Ribosome at A site _blocking _peptidyl transferase _peptide bond synthesis

Azithromycin (Z pack); (Erythromycin, Clarithromycin, Telithromycin)

Reversibly binds 50S subunit _ _translocation via interference with tRNA release; unrelated -agonist at Motilin R. _ _ GI Motility; Resistance via methylation of tRNA

Linezolid

Binds 50S Ribosome and inhibits _ peptidyl transferase

Quinupristin-Dalfopristin

Binds 50S Ribosome and inhibits _ amino-acyl tRNA interaction with acceptor site

Trimethoprim

Folic Acid analogue, inhibits DiHydroFolate Reductase _DHFR _(DHF _ THF), _bacterial recycling of folate, _Purines, AA synthesis

Sulfamethoxazole

PABA analogue, competitively _ dihydropteric synthetase _(PABA _DHF) _DNA synthesis, selective (humans lack de novo folate)

Isoniazid (INH)

Prodrug, activated by catalase-peroxidase (KatG) _INH binds enol-ocyl reductase (InhA), _ disrupting _mycolic acid synthesis

Pyrazinamide

Prodrug; activated by PZase_ pyrazinoic acid_ inhibits mycobacterial fatty acid synthetase I _ _C16, C24 FA, required for mycolic acid synthesis

Ethambutol

Inhibits _ arabinosyl transferases (EmbAB) _ cell wall biosynthesis (arabingalactan)

Acyclovir

Phosphorylated acycloGMP via viral Thymidine Kinase. acycloGTP _ Chain terminator (no 3'OH) & _viral DNA polymerase inhibitor

Ganciclovir

Triphosphate form _ Chain terminator & _viral DNA polymerase inhibitor.

Foscarnet

Inhibits _viral DNA polymerase without need for activation; also _RNA polymerase inhibition

Oseltamivir; (Zanamivir)

Prevent viral release from host cells

Zidovudine (AZT, ZDV, Azidothymidine)

Thymidine analog, tri-phosphorylated by viral enzymes, inhibits HIV's _reverse transcriptase _chain termination; blocks spread of infection; Resitance via mutations in RT

Lamivudine; (Emtricitabine)

Thymidine analog, tri-phosphorylated by viral enzymes, inhibits HIV's _reverse transcriptase _chain termination; blocks spread of infection; Resitance via mutations in RT

Efavirenz; (Nevirapine, Delaviradine; Etravirine)

High affinity, binds (not at catalytic site), _ inhibits HIV's RT do not require metabolic activation

Ritonavir/Lopinavir; Amprenavir

reversibly inhibits _ HIV protease (cleaves HIV polyproteins [gag, gag-pol] to functional parts) virions are packaged but don't mature or infect

Boceprevir; Telapravir

Prevents_ HCV serine protease cleavage of HCV protein into functional subunits

Enfurvitide

Binds first Heptad Repeat (HR1) in _ gp41 envelope glycoprotein, prevents conformational changes require for _fusion to cell membrane

Maraviroc

Binds CCR5 receptor on macs, T-cells, dendritic cells, preventing HIV from using CCR5 as a co-receptor _entry of CCR5-tropic HIV

Raltegravir

Reversibly inhibits _HIV integrase, preventing viral genome transfer to host cell chromosome

Amphotericin B

Binds membrane sterols: _memb. permeability (via pores) _ leakage of K+ and Mg+; selectivity via higher affinity for ergosterol (fungal) vs. cholesterol (mammalian)

Nystatin

Binds membrane sterols: _memb. permeability (via pores) _ leakage of K+ and Mg+; selectivity via higher affinity for ergosterol (fungal) vs. cholesterol (mammalian)

Clotrimazole; Fluconazole (Voriconazole, Terconazole, Posaconazole, Itraconazole)

inhibits _14-_-demethylase (a P450 dependent microsomal enzyme): _ lanosterol _ ergosterol. Destabilizes fungal membrane

Terbinafine (Lamisil); Tolnaftate

Inhibits _ Squalene Epoxidase _ ergosterol synthesis. Destabilizes fungal membrane. Accumulation of squalene is toxic

Caspofungin

Inhibits _ glucan synthase complex _ synthesis of _(1,3)-D-Glucan

Flucytosine

Prodrug activated via fungal cytosine deaminase _ 5-fluorouracil, 5-FU + _ _ 5FdUMP _ active inhibitor of _ Thymidylate synthetase