Snapshot
- A 55-year-old man is in the medical step-down unit for management of his osteomyelitis. The patient has a past medical history of diabetes that is complicated by peripheral neuropathy and gastroparesis. After obtaining a bone culture he is started on empiric antibiotic treatment with vancomycin and ceftriaxone; however, the patient still has a fever. A bone culture grew Pseudomonas aeruginosa that is sensitive to cefepime; his antibiotics were narrowed.
Introduction
- General principle
- rule of thumb
- lower generations favor gram-positive coverage
- higher generations favor gram-negative coverage
- except for 4th and 5th generation, which has extended gram-positive coverage
- rule of thumb
- Drugs
- 1st generation
- cefazolin
- cephalexin
- 2nd generation
- cefoxitin
- cefaclor
- cefuroxime
- 3rd generation
- ceftriaxone
- cefotaxime
- ceftazidime
- cefixime
- 4th generation
- cefepime
- 5th generation
- ceftaroline
- 1st generation
- Mechanism of action
- Mechanism of resistance
- altered penicillin-binding proteins
- production of cephalosporinases
- Clinical use
- 1st generation
- P. mirabilis
- E. coli
- K. pneumoniae
- preventative measure against S. aureus wound infection prior to surgery (cefazolin)
- 2nd generation
- H. influenzae
- Enterobacter aerogenes
- Neisseria spp.
- S. marcescens
- P. mirabilis
- E. coli
- K. pneumoniae
- 3rd generation
- gram-negative infections
- meningitis, gonorrhea, and disseminated Lyme disease (ceftriaxone)
- Pseudomonas (ceftazidime)
- 4th generation
- Pseudomonas
- 5th generation
- gram-negative and gram-positive organisms
- does not cover Pseudomonas
- gram-negative and gram-positive organisms
- 1st generation
- Adverse events
- hypersensitivity reaction
- autoimmune hemolytic anemia
- disulfiram-like reaction
- vitamin K deficiency
- note that there is low cross-reactivity with penicillin (even in penicillin-allergic patients)
- increased nephrotoxicity with aminoglycosides