Cytopenias as Adverse Drug Reactions: A 10-Year Analysis of Reporting Structure, Rate, and Trend

Background/Objectives: Underreporting is very common in drug-induced cytopenias (DICs) due to the late onset of symptoms and the need for laboratory confirmation and monitoring. This research aimed to analyze spontaneously reported adverse drug reaction (ADR) cases of leucopenia, anemia, thrombocytopenia, and total cytopenia, including their reporting structure, rate, and trend, globally (World) and in Serbia. Methods: Based on real-world data from VigiBase, analyses of the DIC reporting structure, rate, and trend over 10 years (2014-2023) were performed. The reporting rate was calculated and expressed as the number of reports per 1,000,000 inhabitants per year (ADR/million/year). Statistics included descriptions, a chi-square test, joinpoint analysis, and measures of variability. Results: Leucopenia was reported more often in Serbia compared to World (1.26 versus 0.96 reports/million/year, respectively), anemia more often in World (2.09 versus 1.75 reports/million/year), while thrombocytopenia reporting was comparable (1.83 reports/million/year globally versus 1.82 reports/million/year in Serbia). In Serbia, there was a constant increase in reporting throughout the observed period, regardless of the cytopenia type, while globally, anemia reports decreased over time. Most of the reported DICs were serious and occurred in females aged 45-64 years. In Serbia, 76.34% of DICs were reported by physicians compared to 31.72% globally. Conclusions: Although upward trends in DIC reporting are observed, variability in reporting between years was greater in Serbia than in World. Many measures are needed to promote the early detection of DICs, with the priority of increasing access to blood count results for all healthcare workers, including pharmacists.