Antibiotics I, II, and III

  1. Penicillin V
    • Beta-lactam - inhibits transpeptidation
    • Broad-spec agains G pos; Nisseria and some anarobes
    • Hypersensitivity rxns
  2. Methicillin
    • Penicillinase-resistant penicillin
    • Good for beta-lactamase producing G pos coccal infx
    • Resistance from failure to bind PBPs
  3. Ampicillin
    • Extended range penicillin
    • First penicillin effective against G neg strains
    • Active against E. coli, P. mirabilis, H. infleunzae, Salmonella, Shigella, and Neisseria
    • "I am extended"
  4. Ticarcillin
    • Anti-Pseudomonal Penicillins
    • Carboxylated derivative of ampicillin
    • Works on P. aeruginosa, Proteus, and Enterobacter
    • "Pseudo-cars have tail pipes"
  5. Cefazolin
    • First generation cephalosporin
    • Narrow spec
    • Surgical prophylaxis
    • Active against Staph and Strep
  6. Cefotetan
    • Second generation cephalosporin
    • Anarobes; use as prophylaxis during intra-abdominal surgery
    • Crosses BBB
  7. Ceftazidine
    • Third generation cephalosporin
    • Good penetration of CNS, bone, lungs, urinary tract
    • Indicated primarily for multidrug-resistant G neg infx, particularly those by P. aeruginosa
  8. Cefipime
    • Fourth generation cephalosporin
    • Works better on G pos than 3rd gen
    • Beta-lactamase resistant
  9. Imipenem
    • Carbapenem
    • Extremely broad spec
    • rapidly hydrolyzed in renal tubule dipeptidase, give with cilastin
    • IV only
    • Not resistant to Beta-lactamase
    • Seizures and renal toxicity
  10. Aztreonam
    • Monobactam
    • Works best on G neg
    • Little cross-allergenicity with other beta-lactams
  11. Vancomycin
    • Glycopeptide
    • Binds to D-ala-D-ala to prevent transglycosylation and transpeptidation
    • No effect on G neg
    • Static for cocci; cidal for rods
    • IV only
    • Use for pseudomembranous colitis or enterocolitis
    • no cross-allergenicity
    • Red man syndrome - hypersensitivity rxn
    • Resistance by changing D-ala
  12. Daptomycin
    • Lipopeptide
    • Inhibits cell membrane potential - forms membrane channels in a calcium-dependent manner leading to rapid depolarization
    • Use for complicated skin infx and endocarditis by aerobic G pos
    • Good for antibiotic-resistant G pos
    • synergizes with oxacillin against MRSA
    • IV only
  13. Cilastin
    • Renal tubule dipeptidase inhibitor
    • Give with imipenem
  14. Clavulanate
    • Suicide inhibitor of beta-lactamase
    • give wtih amoxicillin = Augmentin; with ticarcillin = Timentin
  15. Linezolid
    • Oxazoladinone
    • Binds to 50S and prevents formation of the intiation complex
    • Bacteriostatic against G pos
    • Inhibits MAO; thrombocytopenia, anemia, myelosuppression
  16. Tetracycline
    • Binds 30S ribosomal subunit and prevents binding of the aminoacyl-tRNA during protein synthesis
    • Broad spec against G pos, neg, anaerobic and aerobic; especially good against all rickettsiae
    • Adverse effects: pseudomembranous colitis, tooth discoloration, bone deformation, renal and hepatic toxicity, photosensitivity - not for kiddos
  17. Tigecycline
    • Binds to 30S on the ribosome and inhibits binding of the aminoacyl-tRNA
    • Good for tetracycline-resistant organisms
    • bacteriostatic against G pos and neg
    • IV only
    • TetX = resistance
    • Not for children, infants, pregnant or nursing women
    • Drug interactions with warfarin and OCPs
  18. Streptomycin
    • Binds the 30S subunit irreversibly inhibiting protien synthesis
    • 3 mechanisms of action:
    • 1) interference with formation of the initiation complex
    • 2) misreading -> bacteriocidal
    • 3) premature termination through dissociation
    • Bacteriocidal against G neg
    • Inactive against anaerobes
    • IM or IV -> post antibiotic effect
    • Synergy with beta-lactams
    • ototoxicity, nephrotoxicity, NM blockade
  19. Chloramphenicol
    • Not used in US
    • Binds reversibly to 50 S subunit
    • Broad spec

    • Adverse effects: normocytic anemia (erythroid suppression of bone marrow), idiosyncratic blood dyscrasias, gray baby syndrome
    • interacts with CYP3A4
  20. Erythromycin
    • Macrolide
    • Binds 50S subunit and inhibits the translocation step
    • Wide distribution throughout the body except CSF
    • Interacts with a wide variety of liver p450s
  21. Clindamycin
    • Lincosamide
    • Binds to P and A sites in the 50S subunit
    • Bacteriostatic primarily against G pos cocci
    • effective against anaerobes
    • Does not reach CNS (but will get to bone)
    • Can lead to pseudomembranous colitis
  22. Streptogramins
    • Type A - induces a conformational change in the 50S subunit
    • Type B - binds 50S subunit and inhibits translocation
    • Effective against G pos
    • Use often reserved for VRE or multiple-drug resistant G pos organisms
    • IV only
  23. Telithromycin
    • 50S subunit binding, similar to macrolides
    • G pos and neg bacilli and cocci; mycobacteria
    • Use reserved for community-acquired pneumonia from S. pneumoniae
    • CRITICAL ADVERSE EFFECT: Liver toxicity and failure
    • Potent inhibitor of CYP3A4
  24. Nitrofurantoin
    • Multiple mechanisms of action: DNA damage, binding and inhibition of ribosomal proteins, inhibition of other bacterial enzymes
    • distribution only to the bladder where drug is concentrated in the urine
    • hemolytic anemia with G6PD
  25. Sulfisoxazole
    • Sulfonamides
    • Structural analog and competitive inhibitor of PABA at dihydropteroate synthase -> inhibits folic acid synthesis
    • Bacteriostatic
    • Resistance = decreased permeability, active efflux, increased production of PABA, decreased sensitivity of synthase
  26. Trimethoprim
    • Benzylpyrimidine
    • Selective inhbitor of bacterial isoform of dihydrofolate reductase
    • Broad spec
    • Broad distribution, crosses BBB
    • AE: Megaloblastic anemia, leukopenia, granulocytopenia
  27. Ciprofloxacin
    • Fluoroquinolones
    • Inhibition of bacterial DNA gyrase (topoisomerase II)
    • Mostly G neg, some G pos
    • Imparied by dairy products, antacids, and supplements containing divalent and trivalent cations
    • Not recommended for use in pregnancy, nursing mothers, or children due to potential cartilage damage
    • Increases levels of theophylline
  28. Levofloxacin
    • Fluoroquinolone
    • Inhibits DNA gyrase
    • Don't take with milk or supplements
    • Good for prostatitis
    • Don't use in pregnancy, nursing, or children
    • Interacts with theophylline
  29. Metronidazole
    • Nitroimidazole
    • Inhibits DNA replication -> DNA strand breaks
    • Used primarily for anaerobes, can be used for C. diff
    • AE: seizures and peripheral neuropathy after prolonged therapy, leukopenia
    • Interacts with barbituates which induce liver enzymes
    • Interferes with alcohol metabolism (disulfuram-like rxn)
  30. Rifampin
    • Rifamycins
    • Inhibits bacterial RNA synthesis -> non-covalently binds to beta subunit of DNA-dependent RNA polymerase
Card Set
Antibiotics I, II, and III
Drugs to know from the three antibiotics lectures