Adverse Reactions by Radiopharmaceuticals: Retrospective Analysis of the Portuguese National Pharmacovigilance System

Radiopharmaceuticals are essential in the field of nuclear medicine, but like any other medicinal product, radiopharmaceuticals can potentially cause adverse reactions in patients.

To describe the adverse reactions to radiopharmaceuticals reported to the Portuguese National Pharmacovigilance System (SNF).

We performed a retrospective, observational study by examining individual case safety reports (ICSRs) provided by the SNF related to all radiopharmaceuticals commercially available in Portugal from 2010 to 2023.

The SNF received a total of 84 ICSRs. These reports resulted in a total of 224 adverse drug reactions (ADR), which involved a total of 15 different radiopharmaceuticals. The mean age of patients was 61.9 years old. Twenty-one different system organ classes (SOCs) were identified, with the most prevalent situations being "Gastrointestinal Disorders" (18.3%; n = 41) followed by "General disorders and administration site conditions" (16.5%; n = 37), "Skin and subcutaneous tissue disorders" (11.2%; n = 25) and "Blood and lymphatic system disorders" (10.3%; n = 23). Fifty-seven reports (67.85%) showed at least 1 serious ADR. Most notified radiopharmaceuticals were, respectively, radium-223 (n = 36, 41.4%), lutetium-177 oxotreotide (n = 12, 13.8%) and iodide-131 (n = 9, 10.3%).

Although the number of notifications is limited, these findings provide valuable insights into the types and frequencies of adverse reactions associated with radiopharmaceuticals used in Portugal between 2010 and 2023. The data highlight the importance of continued pharmacovigilance efforts to monitor the safety of these specialized medical products and inform clinical decision-making.