In the United Kingdom, in contrast, single allergen preparations are used and are usually alum (aluminium hydroxide) adsorbed [e.g. Alutard vaccines (ALK Abello)]. Alum acts as an adjuvant [down-regulates T helper type 2 (Th2) cell response/s], and slows the release of the allergen into the tissue and circulation, thereby reducing the incidence of SRs [89,90]. Drug desensitization involves a closely supervised graded administration of a drug to a patient with a history of an immediate hypersensitivity response (IgE-mediated and non-IgE-mediated) to that drug. Although there are no controlled clinical trials to validate the dosage regimens employed,

there are a number of published Gefitinib chemical structure case reports/series supporting the efficacy and safety of this process. Drug desensitization has been carried out successfully SB203580 for a number of IgE-mediated responses, including penicillins, cephalosporins, carbapenems, insulin and platins, as well as for non-IgE-mediated immediate hypersensitivity reactions including aspirin, non-steroidal anti-inflammatory

drugs (NSAIDs), radio contrast media and vancomycin [91–102]. In view of the potential risk of anaphylaxis, this procedure must be considered following a careful ‘risk–benefit’ analysis. There are a few clinical scenarios where such a procedure is indicated (Example 3), and it is prudent to establish that desensitization would be life-saving

or significantly improve clinical outcome or quality of life in the patient. Life-threatening or serious infections where no alternative antibiotic is available: In contrast to desensitization with aero-allergens and venoms, where long-term tolerance can be established following a 3–5-year treatment course, tolerance induced by drug desensitization is lost within a few days of stopping the drug [103]. In other words, the process of desensitization has to be repeated each time the patient is exposed to the specific drug after a period of discontinuation. Drug desensitization is principally carried out orally and intravenously, the former being a safer approach. Rapid desensitization protocols have been developed where the therapeutic dosage can be administered within a few hours. Often the starting dose is ≤ 1/1000th Phosphatidylinositol diacylglycerol-lyase the therapeutic dosage, with escalations being carried out in doubling doses at 15–30-min intervals, monitoring the patient closely for symptoms and signs of an allergic reaction. Intravenous desensitization usually involves preparation of three different concentrations of the drug (solutions A, B, C), with a 10-fold increase in concentration between A and C. The rate of infusion of each solution is regulated with a syringe pump in such a way that there are four incremental dosage steps at 15–30-min intervals for each solution.