Age disparities in adverse reactions of drugs used in pain therapies in Switzerland

Pain therapies are prescribed to a significant proportion of the population but also associated with adverse drug reactions (ADRs). The prescription of pain therapies requires careful consideration of their safety profiles in the context of patient-specific characteristics, such as age-specific vulnerabilities, which are, however, still understudied so far. The aim of this study was to describe ADRs reported for drugs used in pain therapies and investigate age disparities. We conducted a descriptive comparative analysis of individual case safety reports (ICSRs) of drugs used in pain therapies from the global ADR database VigiBase between September 29, 1991, and December 31, 2022, from Switzerland. Comparisons were drawn between younger and older adults (18-74 years vs. 75 + years). Disproportionality (reporting odds ratio, ROR) of serious ADRs was assessed between age groups. A total of 17,228 ICSRs were analysed (58% female, 24% age 75 +). Across both age groups, the most frequently reported ADRs were related to the nervous system (23%), gastrointestinal system (20%), and general health and administration site conditions (20%). Serious ADRs were more common in the older population compared to younger adults (69% vs. 54%) with an ROR of 1.9. Fatal ADRs were also disproportionally higher in older adults (ROR 1.9). Hemorrhage was the most frequent fatal reaction. Commonly used pain therapies can lead to ADRs with a pronounced impact, especially in older adults. A deeper understanding of the safety profiles of these drugs should aid healthcare professionals in making more informed, safer treatment decisions.