Successful Desensitization Protocol for Hypersensitivity Reaction Caused by Irinotecan in a Patient With Metastatic Colorectal Cancer

Irinotecan is widely used in the treatment of gastrointestinal malignancies. Generalized hypersensitivity reactions (HSRs) to irinotecan have been described previously, but desensitization has not been reported in the English literature. The current case presents a patient with colorectal cancer who developed a type 1 HSR to irinotecan and was successfully treated with a rapid drug desensitization protocol. The described protocol provides an example and can serve as a reference for rapid desensitization to irinotecan, which appears to be an option for patients with HSRs to it. This approach might permit clinicians to safely administer irinotecan to patients who experience HSRs to this life-prolonging medication.