Systemic therapy emergencies

Systemic oncologic therapies can cause multiple emergency situations. There are, however, two unique emergencies directly related to chemotherapy administration: drug extravasation and hypersensitivity reactions (HSRs). Most drugs can cause varying degrees of local tissue injury when extravasated. The medical management of extravasation is based on proper maintenance of the intravenous line, application of local cooling or warming for certain extravasations, and the use of antidotes to prevent the local toxic action of the extravasated drug. Antidotes that appear useful include hyaluronidase (for vinca alkaloids, epipodophyllotoxins, and paclitaxel), sodium thiosulfate (for mechlorethamine and cisplatin), and dimethylsulfoxide (DMSO) (for anthracyclines and mitomycin C). HSRs, another potential adverse effect of chemotherapy administration, are a major concern for therapy with taxanes and with L-asparaginase, and their administration requires the use of premedication to prevent these reactions. Once a HSR has occurred, therapy may be continued by using an analog drug or by the administration of premedication as prophylaxis, in particular if the reaction was minor. On the other hand, it is also pertinent to become acquainted with the emergencies induced by biological agents, taking into consideration their increasing usages. In addition to interferons and interleukin-2 (IL-2), both of which have been in clinical use for several years, cytokine-toxin fusion proteins (DAB3891L-2) and two monoclonal antibodies (rituximab and trastuzumab) were recently approved for cancer therapy. The distinct toxicity profiles of these agents are reviewed.