Anaphylactoid reactions associated with ondansetron

To describe two patients with anaphylactoid-type reactions to ondansetron.

A 41-year-old man with grade III leiomyosarcoma of the right tibia was admitted to the hospital for his second dose of first-cycle neoadjuvant intraaterial cisplatin 60 mg/m2 therapy. He experienced an anaphylactoid reaction following intravenous ondansetron infusion that was confirmed on rechallenge. In a second case, premedication with intravenous ondansetron resulted in an anaphylactoid reaction in a 44-year-old woman with stage III ovarian cancer receiving her ninth course of cyclophosphamide and carboplatin. Both patients had received ondansetron previously with no adverse effects.

Peer-reviewed journal articles and reports, obtained through a MEDLINE search, were reviewed. Information on the individual cases was obtained from the patients' medical records. Preservative changes in ondansetron infusion were examined as possible causes of the anaphylactoid reactions in our patients, but no conclusive data linking them were found.

The efficacy and safety of ondansetron has led to the widespread use of this medication in the treatment of nausea and vomiting caused by cancer chemotherapy and radiation therapy. Practitioners should be made aware that acute severe anaphylactoid reactions could occur in patients who have previously received ondansetron with no adverse effects.