Protein synthesis inhibitors Abx

  1. Which are 30S inhibitors and 50S inhibitors?
    • 30S:
    • A-Aminoglycosides (streptomycin, gentamicin, tobramycin, amikacin) (bactericidal)
    • T-Tetracyclines (bacteriostatic

    • 50S:
    • C-Chloramphenicol, Clindamycin (bacteriostatic)
    • E-Erythromycin (bacteriostatic)
    • L-Lincomycin (bacteriostatic)
    • L-Linezoid (variable)

    "Buy AT 30, CCELL (sell) at 50."
  2. MOA of aminoglycosides and types
    • Inhibits formation of initiation complex and cause misreading of mRNA.
    • Required O2 for uptake, thus NOT effective against anaerobes.

    Gentamicin, neomycin, amikacin, tobramycin, streptomycin, paromomycin (safe for preggers)
  3. Clinical use of aminoglycosides
    Severe GNRs infxs. Synergistic with beta-lactams. Neomycin for bowel surgery.
  4. Toxicity of aminoglycosides
    • Nephrotoxicity (esp when used with ceph)
    • Ototoxcitiy (esp when used with LOOP diuretics)
    • Teratogen
  5. MOA of tetracyclines and i.e
    • Binds to 30S and prevent attachment of aminoacyl-tRNA
    • Limited CNS penetration
    • Doxycycline is fecally eliminated and can be used in pts with renal failure
    • AVOID dairy, antacids, or Fe-containing prep bc divalent cations inhibit its absorption in the gut.

    Tetracycline (1st line for mycoplasma spp), doxycycline, demeclocycline, minocycline
  6. Clinical use of tetracyclines
    Vibrio cholerae, P. acne, chlamydia, ureaplasma, urealyticum, mycoplasma pneuomoniae, tularemia, H.pylori, borrelia burgdorferi, rickettsia
  7. Toxicities of tetracyclines
    GI stress, discoloration of teeth, blue-ish skin hues, inhibition of bone growth in children, photosensitivity.

    C/I in preggers
  8. MOAs of Macrolides and
    Inhibit protein synthesis by blocking translocation; bind to the 23S rRNA of the 50S ribosomal subunit.

    • Erythromycin (1st line for legionella b/c legionella produces beta lactamases)
    • Azithromycin
    • Clarithromycin (1st line for mycoplasma) (Biaxin)
  9. Clinical use of macrolides
    • URIs, pneumonias, STDs
    • GPCs (streptococcal infxn in pts allergic to pen.)
    • Mycoplasma, Legionella, Chlamydia, Neisseria
  10. Toxicity of macrolides
    • GI discomfort (MCC of noncompliance)
    • Acute cholestatic hepatitis
    • Eosinophilia, skin rashes
    • Increases serum concentration of theophyllines, oral anticoagulants
  11. MOAs of chloramphenicol
    Inhibits 50S peptidyltransferase activity. Inhibit peptide bond formation.

  12. Clinical use of chloramphenicol
    Meningitis (H. influenzae, N. meningitidis, S. pneumo)

    conservative use owing to toxicities
  13. Toxicities of chloramphenicol
    • Anemia (dose dependent)
    • Aplastic anemia (dose independent)
    • Gray baby syndrome (esp in premies infants bc they lack liver UDP-glucuronyl transferase)
  14. MOA of Clindamycin
    Block peptide bond formation at 50S ribosomal subunit

    Brands--Cleocin, Clindesse
  15. Clinical Use/Toxicities of Clindamycin
    Tx anaerobic infxns (i.e bacteroides fragilis, clostridium perfringens)

    Pseudomembranous colitis (C. difficile overgrowth), fever, diarrhea
Card Set
Protein synthesis inhibitors Abx