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 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 Adverse effects irreversible ototoxicity (cochlear and vestibular) increased with loop diuretics nephrotoxicity increased with cephalosporins neuromuscular blockade teratogen