Immediate severe hypersensitivity reaction to etoposide phosphate: Case report and review of the literature.

Hypersensitivity reactions to etoposide were first reported in the 1980s. Following reactions to etoposide, substituting etoposide phosphate into chemotherapy regimens has commonly allowed treatment to continue without incidence. Anaphylactic reactions to etoposide phosphate were first documented in 2012, with further cases reported subsequently. Unlike etoposide, etoposide phosphate is highly soluble in aqueous solutions and doesn't require adjuvants in the formulation. Hypersensitivity reactions to etoposide phosphate are therefore likely related to the etoposide drug molecule itself. Clinicians should be aware of this rare, but potentially life-threatening, toxicity when using etoposide-based treatments and have procedures in place to urgently manage any hypersensitivity reactions that may occur.