Amphotericin B

Snapshot

• A 36-year-old man presents to the emergency department with an altered level of consciousness and fever. He is accompanied by a friend, who says that prior to being altered, he experienced a productive cough, chills, and night sweats. His temperature is 103°F (39.4°C), blood pressure is 70/60 mmHg, pulse is 130/min, and respirations are 14/min. He is immediately started on intravenous fluids, blood cultures are drawn, is started on vancomycin and piperacillin/tazobactam, and is admitted to the medical intensive care unit. In the unit, the patient is stabilized but is still febrile. KOH and calcofluor white are added to fresh wet preparations of the patient’s sputum, which demonstrate refractile cell wall, and single, broad-based buds. He is then started on intravenous amphotericin B. (Blastomycosis)

Introduction

• Mechanism of action
  • binds to ergosterol, which leads to the formation of pores in fungal membranes leaking its internal cellular contents   
• Mechanism of resistance
  • alterations in ergosterol
• Clinical use
  • serious (potentially life-threatening) systemic mycoses 
    • aspergillosis
    • cryptococcosis
    • blastomycosis 
    • systemic candidiasis
    • coccidioidomycosis
    • histoplasmosis
    • zygomycosis
    • fungal meningitis
      • medication must be administered intrathecally to target the central nervous system
• Adverse effects
  • nephrotoxicity
    • hydration decreases the risk
  • intravenous phlebitis
  • anemia
  • cardiac arrhythmia
  • fevers and chills
  • hypokalemia and hypomagnesemia  
    • should supplement these electrolytes in patients in treatment