Objective: To report a case of accidental amphotericin B overdose that was treated with plasmapheresis.
Case summary: A 60-year-old woman with a history of kidney transplant 4 years prior to presentation for a congenital abnormality was admitted for a suspected systemic fungal infection. The patient inadvertently received intravenous amphotericin B deoxycholate 250 mg (4.3 mg/kg) over 2 hours instead of prescribed liposomal amphotericin B. The medication error was discovered 16 hours after administration. She had normal vital signs at that time and reported abdominal pain and general malaise. Results of a metabolic panel were significant for a creatinine level of 2.1 mg/dL and CO₂ of 17 mg/dL. Her serum amphotericin B concentration 33 hours after the initial dose was 4.9 μg/mL. She subsequently received 5 courses of plasmapheresis and 3 courses of hemodialysis and ultimately did not develop any further renal injury, as well as hemolysis, cardiovascular collapse, dysrhythmias, or severe electrolyte abnormalities.
Discussion: The dosing differences between nonliposomal and liposomal preparations of amphotericin B can be as high as 50-fold. Reported adverse events from overdose in both animal models and human case reports include renal insufficiency, hemolysis, thrombocytopenia, electrolyte abnormality, and cardiac dysrhythmias. There have been previous reports of similar errors that have led to death. Furthermore, amphotericin B has been shown to be poorly dialyzable. Our patient's serum amphotericin B concentration decreased after she received plasmapheresis, and she did not develop severe complications.
Conclusions: We describe a patient who survived a 4-fold overdose of amphotericin B because of a medication error. The use of plasmapheresis may have enhanced the elimination of amphotericin B and may have contributed to the positive outcome. However, the role of plasmapheresis in amphotericin overdose is not fully understood.