Aztreonam

Snapshot

• A 28-year-old woman presents to her primary care physician due to dysuria. Her symptoms began approximately 2-3 days ago and have progressively worsened. She has a past medical history of mild asthma. She is allergic to penicillin, which causes her to have a severe skin rash and shortness of breath. Her symptoms are associated with urinary urgency and frequency. Physical examination demonstrated tenderness to palpation of the suprapubic region. A urinalysis and urine culture are ordered, which demonstrates Proteus mirabilis infection. She is treated with aztreonam.

Introduction

• Mechanism of action
  • a monobactam that binds to penicillin-binding proteins 3 (PBP-3), which inhibits transpeptidation
    • impairs peptidoglycan synthesis, a needed component of cell wall biosynthesis
    • no cross-allergy with penicillins
• Mechanism of resistance
  • altered PBP-3
• Clinical use
  • gram-negative rods only  
    • especially in patients who are allergic to penicillins or intolerable to aminoglycosides
• Adverse effects
  • gastrointestinal upset (occasional)