Drug-induced radiation recall reactions and non-anticancer drugs: A descriptive analysis from VigiBase®

Radiation recall reactions are inflammatory reactions confined to previously irradiated tissues, often of drug-induced etiology, particularly with anticancer therapies. Other drugs, in particular COVID-19 vaccines, may also be involved. To describe radiation recall reactions under non-anticancer drugs more precisely, we extracted the cases of radiation recall reactions associated with non-anticancer drugs from WHO pharmacovigilance database VigiBase®. We performed two analyses from this extraction: a global analysis and an analysis focusing on vaccination-related issues. We extracted 120 cases corresponding to 269 drugs, of which 130 were non-anticancer (22 vaccines). Among the non-anticancer drugs, tozinameran was the most reported treatment (4.46% of cases), followed by levofloxacin (2.97%) and folinic acid (2.60%), dexamethasone (2.23), and ChAdOx1 nCoV-19 vaccine and prednisone (1.86% each). Among vaccines, tozinameran (54.55% of cases) was the most reported, followed by ChAdOx1 nCoV-19 (22.73%), HPV and inactivated influenza vaccine (9.09% each), and elasomeran (4.55%). Our study first describes the occurrence of radiation recall reactions during non-anticancer treatment. It also highlights a potential safety signal with COVID-19 vaccines.