Pseudohyperphosphatemia associated with high-dose liposomal and lipid complex amphotericin B when tested with Synchron LX 20 (Beckman/Coulter) phosphorous assay.

Although case reports of hyperphosphatemia have been previously described in patients receiving liposomal amphotericin B, this has not been reported in patients receiving the lipid complex formulation. We report a case of hyperphosphatemia that persisted despite switching from liposomal to lipid complex amphotericin B in a child with invasive zygomycosis. This case suggests that in the context of acute renal dysfunction, hyperphosphatemia may also be observed with lipid complex amphotericin B. This case highlights the importance of differentiating between pseudohyperphosphatemia and hyperphosphatemia to prevent complications.