Source / episode info
- **Episode:**28
- **Title:**Divine Intervention Episode 28 – Antibiotics Part 2 (Protein Synthesis Inhibitors).
- **Published:**2018-05-13
- Source:Episode page
One-liner
This episode details antibiotics that inhibit protein synthesis by targeting the bacterial ribosome (70S), focusing on drugs like aminoglycosides (30S inhibitors), macrolides/lincosamides (50S inhibitors), and tetracyclines (A-site inhibitors), while reviewing associated toxicities, coverage patterns, and P450 metabolism.
High-yield summary
- Aminoglycosides (Gentamicin, Neomycin, Amikacin): 30S inhibitors; cover primarily Gram-negative rods; nephrotoxic (ototoxicity/nephrotoxicity); no anaerobic coverage; used for GI flora control in HE.
- Macrolides/Lincosamides (Azithromycin, Clindamycin, Linezolid): 50S inhibitors; inhibit translocation; Macrolides are associated with GI upset and risk of pyloric stenosis; Lincosamides (Clindamycin) cover anaerobes above the diaphragm.
- Tetracyclines (Doxycycline, Minocycline): 30S inhibitors; broad spectrum; contraindicated in children <8 years old due to chelation by divalent ions leading to tooth/bone discoloration.
- Chloramphenicol: Potent Gram-positive and Gram-negative coverage; used for severe infections (e.g., meningitis, RMSF in pregnant women); toxic due to inhibition of UDPGT, causing aplastic anemia and Gray baby syndrome in neonates.
- P450 Metabolism: Macrolides are P450 inhibitors; Rifampin is a potent P450 inducer. This interaction is critical for drug dosing (e.g., birth control failure).
Learning objectives
- Differentiate between 30S and 50S ribosomal inhibitors, naming key drugs for each class.
- Correlate specific antibiotic classes with their primary coverage (e.g., aminoglycosides vs. anaerobes).
- Recognize the unique toxicities associated with high-yield antibiotics (Chloramphenicol, Macrolides, Aminoglycosides).
- Understand the clinical implications of P450 enzyme induction and inhibition by various drugs.
- Apply antibiotic knowledge to common infectious scenarios like C. difficile colitis or Lyme disease.
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