Desensitization for the prevention of drug hypersensitivity

Abstract

Drug desensitization is a treatment strategy for patients with hypersensitivity to essential drugs without alternatives. The gradual increase in the drug dosage from low doses to therapeutic levels induces a transient immune tolerance to the culprit drug. Although desensitization has traditionally been recommended for IgE-mediated immediate hypersensitivity, this indication has recently been expanded to include non-IgE-mediated immediate responses, nonimmunological responses, and T-cell mediated delayed hypersensitivity reactions. Although the exact mechanism behind desensitization remains unclear, the process is thought to attenuate various intracellular signals in target cells through the high-affinity IgE receptor (FcɛRI) internalization, alteration in signaling pathways in mast cells and basophils, reduction in Ca2+ influx, and production of anti-drug IgG4 blocking antibody. Desensitization can be used for the safe administration of anti-neoplastic agents, antibiotics, aspirin, and nonsteroidal anti-inflammatory drugs. Various desensitization protocols have been proposed for each drug. The optimization of drug concentration, target dosage, administration interval, and route of administration is key to successful desensitization. In addition, the desensitization protocol should be individualized for each patient with consideration of the severity of the initial hypersensitivity response, the characteristics of the culprit drug, and the nature of the breakthrough reactions.