Adverse drug reactions in older adults: a retrospective comparative analysis of spontaneous reports to the German Federal Institute for Drugs and Medical Devices

BACKGROUND: Older adults are more prone to develop adverse drug reactions (ADRs) since they exhibit numerous risk factors. The first aim was to analyse the number of spontaneous ADR reports regarding older adults (> 65) in the ADR database of the German Federal Institute for Drugs and Medical Devices (BfArM) and to set them in relation to i) the number of ADR reports concerning younger adults (19–65), and ii) the number of inhabitants and assumed drug-exposed inhabitants. The second aim was to analyse, if reported characteristics occurred more often in older vs. younger adults. METHODS: All spontaneous ADR reports involving older or younger adults within the period 01/01/2000–10/31/2017 were identified in the ADR database. Ratios concerning the number of ADR reports/number of inhabitants and ADR reports/drug-exposed inhabitants were calculated. The reports for older (n = 69,914) and younger adults (n = 111,463) were compared using descriptive and inferential statistics. RESULTS: The absolute number of ADR reports involving older adults increased from 1615 (2000) up to 5367 ADR reports (2016). The age groups 76–84 and 70–79 had the highest number of ADR reports with 25 ADR reports per 100,000 inhabitants and 27 ADR reports per 100,000 assumed drug-exposed inhabitants. For both ratios, the number of reports was higher for males (26 and 28 ADR reports) than for females (24 and 26 ADR reports). Fatal outcome was reported almost three times more often in older vs. younger adults. Six out of ten drug substances most frequently suspected were antithrombotics (vs. 1/10 in younger adults). For some drug substances (e.g. rivaroxaban) the ADRs reported most frequently differed between older (epistaxis) and younger adults (menorrhagia). CONCLUSIONS: There is a need to further investigate ADRs in older adults since they occurred more frequently in older vs. younger adults and will likely increase in future. Physicians should be aware of different ADRs being attributed to the same drug substances which may be more prominent in older adults. Regular monitoring of older adults taking antithrombotics is recommended.