Lithium‐related adverse drug reactions in children: A case–control study comparing lithium to second‐generation antipsychotics in VigiBase

AIMS: This study aimed to improve the understanding of lithium's safety profile by analysing the frequency and distribution of reported adverse drug reactions (ADRs) compared to second-generation antipsychotics (SGAs). METHODS: Individual case safety reports from VigiBase (1968-October 2023) involving individuals older than 2 years, with lithium or SGAs as a suspected or interacting drug, were included. Medical Dictionary for Regulatory Activities (MedDRA) was used for ADRs classification. Proportional reporting ratios (PRRs) with 95% confidence intervals were calculated across different age groups. RESULTS: The lithium group contained 29 897 reported ADRs. Proportional reporting patterns varied across age groups. In children, lithium was associated with a higher proportion of renal, endocrine, gastrointestinal, skin and cardiac ADRs compared to SGAs. SGAs showed proportionally more ADRs in females, whereas lithium displayed fewer and more balanced sex-related differences. Renal impairment accounted for a larger proportion of lithium-related ADRs in older adults compared to children. For SGAs, type 2 diabetes and cardiovascular events showed higher proportional reporting in both younger and older adults than in children. In contrast, thyroid-related ADRs with lithium and weight-related ADRs with SGAs were proportionally more common in children. CONCLUSIONS: Renal, endocrine and gastrointestinal effects are observed in children using lithium, though serious outcomes like renal failure appear proportionally more often in older adults. SGAs also show age-specific risk patterns, particularly metabolic and cardiovascular effects in adults. This emphasizes the ongoing need for individualized treatment and continued ADR monitoring and reporting to enhance the understanding of lithium's safety profile and support informed clinical decision-making.