Snapshot
- A 24-year-old woman presents to the emergency room for abdominal pain and foul-smelling discharge from her vagina. About 4 days ago, she gave birth to twins via C-section and was sent home without complications. Yesterday, she developed a fever as well as abdominal pain. On physical exam, there is significant tenderness to palpation. She is started on intravenous antibiotic therapy with 2 agents, covering both anaerobes and aerobic gram-negative organisms. (Postpartum endometritis)
Introduction
- Drugs
- amikacin
- gentamicin
- neomycin
- streptomycin
- tobramycin
- Mechanism of action
- irreversibly binds to 30S subunit of bacterial ribosomes
- prevents initiation complex from forming
- causes misreading of genetic code
- requires oxygen for uptake and is effective only against aerobes
- works synergistically with beta-lactams
- bactericidal
- irreversibly binds to 30S subunit of bacterial ribosomes
- Mechanism of resistance
- bacterial enzymes inactivate the drug by modifying it through adenylation, acetylation, or phosphorylation
- Clinical use
- severe aerobic gram-negative rod infections
- including Pseudomonas aeruginosa, Acinetobacter, Nocardia, and Actinomycetes
- P aeruginosa resistant to gentamicin and tobramycin are often susceptible to amikacin
- neomycin for bowel surgery
- topical neomycin for superficial skin infections
- severe aerobic gram-negative rod infections
- Adverse effects
- nephrotoxicity
- increased with cephalosporins
- neuromuscular blockade
- teratogen
- nephrotoxicity