Desensitisation is a procedure that is undertaken in hypersensitive patients in order to induce immunological tolerance to the culprit drug. The tolerance is temporary and once the treatment is interrupted or discontinued the hypersensitivity returns. The commonest desensitisation procedure is that of rapid intravenous desensitisation in patients with immediate hypersensitivity reactions; other routes of desensitisation include oral and subcutaneous protocols. The mechanisms are not fully understood; however, there is clinical evidence to support its effectiveness for antibiotics, chemotherapy, and biological agents. Procedures should be performed when there is an absolute need for the drug but is contraindicated in severe T cell mediated reactions, such as Stevens-Johnson syndrome. It should only be performed by clinicians experienced in the procedure.
Typical rapid intravenous desensitisation is based around a 12-step protocol which starts with an extremely dilute solution that doubles in dose every 15 minutes. In patients with severe anaphylactic reactions, a slower 16-step protocol can be used.
General considerations for rapid drug desensitisation (2010), please click here for details.
Desensitisation in non-immediate reactions (2013), please click here for details
Undertaking drug desensitisation requires training and expertise in allergy practice and an understanding of drug allergy. Standardized protocols for drug desensitisation have become accepted practice and allow administration of drugs which would otherwise have been contraindicated. BSACI have developed an intravenous drug desensitisation calculator on their website using a protocol developed by Brigham and Women’s Hospital, Boston. USA.. Patients considered for drug desensitisation must be carefully selected by a clinician trained in drug allergy and the decision to desensitise and use of the calculator will remain the responsibility of the user. The final protocol must be checked and verified by the clinician before the patient undergoes desensitisation. To access the drug calculator please click here
NOTE: NO INFORMATION IS COLLECTED/HELD ON THE DRUG CALCULATOR