Trastuzumab infusion reactions in breast cancer. Should we routinely observe after the first dose?

Trastuzumab (Herceptin) is used in neoadjuvant, adjuvant and metastatic breast cancer. Infusion reactions are a common side effect most of which are mild and easily managed, anaphylaxis occurs rarely. The summary of product characteristics recommends observation for 6 hours after the commencement of the first administration; we wanted to evaluate this practice. We assessed first administrations of trastuzumab infusions retrospectively to determine both rate and timing of reactions. Medical and nursing notes of 94 patients who had been prescribed intravenous trastuzumab in 2012 were reviewed; 2 additional patients did not have records available. Fourteen patients received palliative, 73 adjuvant and 7 neoadjuvant trastuzumab.r. Two (2%) had a reaction to trastuzumab occurring at 70 and 80 min from infusion commencement. We did not observe a reaction in the 4.5 hours after the 90 min infusion was complete. We recommend discharge with verbal and written advice immediately after uncomplicated first administration.