Antimicrobials Flashcards
Isoniazid (INH)
Anti-biotic
Inhibits synthesis of mycolic acid
Prophylaxis for mycobacteirum infections
Cotrimoxazole (Bactrim)
Anti-biotic
Inhibits folate metabolism
Mixture of sulfonamide and trimethoprim
***cillins - Penicillin, Methicillin, Amoxicillin, Nafcillin
Inhibit cell wall synthesis by covalently/irreversibly binding and inactivating transpeptidases (act as suicide substrates)
Penicillin: Syphilis
Nafcillin: MSSA
What was the first orally available penicillin?
AmOxicillin
Gram + bacteria have what 2 things in their cell walls?
Peptidoglycans, lipoteichoic acids
Gram - bacteria have what in their cell walls?
LPS
What enzyme do bacteria synthesize to resist penicillin?
Penicillinase aka beta-lactamase (opens the beta-lactam ring in penicillin)
How does penicillin work?
Covalently/irreversibly binds transpeptidases (rqd for cell wall sythesis) and inactivates them
Augmentin
Antibiotic - inhibits penicillinase
Amoxicillin + clavulanic acid
Zosyn
Antibiotic
Piperacillin + tazobactam (inhibits pencillinase)
Intensive care setting and covers both Gram + and - organisms
Are penicillins more effective against Gram + or Gram - bacteria?
Gram +
Cephalosporins (Cef***) - Cefazolin, Cefoxitin, Ceftriaxone, Cefepime
Anti-biotic - inhibits cell wall synthesis by irreversibly binding to transpeptidases
More resistant to beta-lactamases, has less hypersensitivity rxns, and more Gram (-) coverage
1st gen: MSSA, PEK
2nd gen: MSSA, HENPECK
3rd gen: community-acquired pneumonia, meningitis
Gram (-) Bacteria - PEKHEN
Proteus, E coli, Klebsiella, Haemophilus, Enterobacter, Neisseria
Gram (+) Bacteria - CLEPSS
Clostridium, Listeria, Enterococcus, Pneumococcus, Staph, Strep
Vancomycin
Anti-biotic
Inhibits cell wall synthesis - binds D-alanine and prevents transpeptidase enzyme for cross-linking
MRSA
**floxacins/Fluoroquinolones - Cipro/Ciprofloxacin and Moxifloxacin
Antibiotic - inhibit DNA gyrase
Community-acquired pneumonia
Newer generation drugs have less _____ coverage and more ____ coverage.
Less Gram +, more Gram -
Rifampin/Rifamycin
Inhibits bacterial RNA polymerase; also mitochondrial RNA polymerase
TB
**cycline - Tetracycline
Antibiotic - inhibit protein synthesis
Bacteriostatic vs. bactericidal
Stop bacterial growth vs. kill bacteria
Narrow spectrum vs. broad spectrum
Narrow spectrum - covers one or a couple bugs
Broad spectrum - covers lots of bugs
What antibiotic can cause anaphylactic rxn due to allergies?
Penicillin