In most cases, the suspected drug is simply avoided in the future. However, for certain patients, the particular drug may be essential for optimal therapy. Under these circumstances, desensitization may be performed.
Drug desensitization is defined as the induction of a temporary state of tolerance of a drug responsible for a hypersensitivity reaction. It is performed by administering increasing doses of the medication concerned over a short period of time (from several hours to a few days) until the total cumulative therapeutic dose is achieved and tolerated.
Drug desensitization is a high-risk procedure used only in patients in whom alternatives are less effective or not available after a risk/benefit analysis.
Desensitization protocols have been developed and are used in patients with allergic reactions to antibiotics (mainly penicillin), insulins, sulfonamides, chemotherapeutic and biologic agents, and many other drugs.
Desensitization is mainly performed in IgE-mediated reactions, but also in reactions where drug-specific IgE have not been demonstrated.
Desensitization induces a temporary tolerant state, which can only be maintained by continuous administration of the medication.
Thus, for treatments like chemotherapy, which have an average interval of 4 weeks between cycles, the procedure must be repeated for every new course.
General considerations on rapid desensitization for drug hypersensitivity - a consensus statement. Cernadas JR, Brockow K, Romano A, Aberer W, Torres MJ, Bircher A, Campi P, Sanz ML, Castells M, Demoly P, Pichler WJ; for the European Network of Drug Allergy and the EAACI interest group on drug hypersensitivity. Allergy. 2010 Aug 17.