Elizabeth was caring for a patient who required liposomal amphotericin B (Ambisome) for a CNS fungal infection. However, the patient had an order placed for amphotericin B deoxycholate ("conventional" formulation) 5 mg/kg IV daily. While 5 mg/kg is the correct dose for liposomal amphotericin B (Ambisome), it is a 5-fold overdose of amphotericin B deoxycholate (conventional), which the patient was ordered for. This is a known fatal medication error that can result in cardiac arrest. Upon programming the medication and dose in the infusion pump, an alert fired for a high dose. Although the pump allows the programmer to override and proceed with the dose, Elizabeth contacted the pharmacist to confirm the dose at which point the dosing error was discovered. Elizabeth's exemplary action to "stop the line" prevented the administration of a potentially fatal dose of amphotericin. As a result, many system-based fixes were implemented and are in the process of development to prevent this and other potentially fatal medication errors from happening again.