Confusion between Two Amphotericin B Formulations Leading to a Paediatric Rehospitalisation

A heavily immunosuppressed, 43-kg, 9-year-old patient was recovering from a bone marrow transplant. Primary prophylaxis against invasive fungal infections was liposomal amphotericin B (AmBisome(®), 2.3 mg/kg [100 mg] two times per week). Once home, following a first amphotericin B infusion, he presented with strong diarrhoea and vomiting; this was repeated after the second infusion. The clinical situation worsened rapidly and the patient was rehospitalised. On admission, he presented with acute renal failure. During the 2-week hospitalisation, renal function recovered progressively. A few days after returning home, a new administration of amphotericin B was again followed by diarrhoea and vomiting, together with shivering and fever. The child was again rapidly rehospitalised. Investigation revealed that the community pharmacist, relying on drug software, had selected an inappropriate substitute drug: the patient had been administered amphotericin B deoxycholate (Fungizone(®)) and not liposomal amphotericin B. Depending on the indication, intravenous AmBisome(®) is usually administered at a dose between 3 and 5 mg/kg bodyweight; this dose can be increased to up to 10 mg/kg/day. Intravenous Fungizone(®), however, should be administered using an initial dose of 0.25 mg/kg bodyweight, up to a recommended 1-mg/kg/day dose. The child had thus received 100 mg of Fungizone(®), or ten times the recommended dose.