Single center experience with more than 600 drug desensitization in Colombia.

Background: Drug hypersensitivity reactions (DHRs) have a significant impact on both, patient and their treating physicians; it is considered a public health concern. The history of allergy to drugs, limits therapeutic options and will lead to the use of more expensive and potentially less effective options. Drug desensitization (DD) is considered as a procedure with a positive impact on the prognosis of the patient's disease. The objective of this study is to describe the experience with a substantial number of drugs desensitization in a fourth level center in Cali, Colombia.

Methods: An observational, cross-sectional and descriptive study was conducted. Patients with DHRs who underwent a standardized institutional DD protocol, between March of 2012 and May of 2023, were included.

Results: Two hundred forty-one patients were included. The median age was 47.8 years (4-88). One hundred fifty-six (64.7%) were women, including three who were pregnant. A total of 641 DDs were performed. The most frequent groups of drugs for which the desensitization was performed were monoclonal antibodies in 83 patients (34.4%), chemotherapeutic agents in 53 (21.6%), NSAIDs in 44 (18.2%), and antibiotics in 42 (17.4%). Eighty-seven patients (36.1%) experienced hypersensitivity to the culprit drug on first exposure, while 154 (63.9%) exhibited reactions during subsequent cycles. The main clinical presentation that gave rise to desensitization was anaphylaxis in 125 patients (51.8%), followed by cutaneous symptoms in 106 patients (44%). The predominant observed endophenotype was type 1 in 188 patients (78.3%), followed by mixed type in 46 patients (19.2%). Breakthrough reactions were observed in 50 patients (20.7%). Tolerance to DD was achieved in 636 of the procedures (99.2%), allowing the continuity of treatment of choice for the underlying disease.

Conclusions: Most desensitized patients were women with type I reactions. Monoclonal antibodies were the most frequent culprit drugs. DD in patients with DHRs is a useful, safe and effective procedure. The administration of the implicated drug had a positive impact on the course of the disease in these patients.