Revisiting Safety Assessments of Baclofen and Tizanidine in Older Adults

We read with great interest the study by George et al. assessing the safety of baclofen and tizanidine in older adults using a large retrospective cohort from Kaiser Permanente Southern California [1]. The findings that both agents were associated with higher risks of serious injury compared to cyclobenzaprine are clinically important, particularly in the context of updating prescribing recommendations for older patients. However, one design feature warrants further reflection. The study excluded individuals who had encounters with skilled nursing facilities, hospice, or palliative care in the year before or during follow-up. While this decision aimed to remove frail and highly vulnerable patients, it inadvertently omits the very subgroup most likely to experience adverse drug events from centrally acting skeletal muscle relaxants. Residents in hospice or long-term care facilities frequently present with multimorbidity, functional dependence, and polypharmacy, all of which amplify the risk of sedation, falls, and fractures [2]. By excluding these patients, the study population may represent a healthier subset of older adults, potentially leading to an underestimation of the true safety concerns in routine geriatric practice. The outcome definition primarily relied on fractures and major injuries. However, less severe yet clinically meaningful harms—such as delirium, urinary retention, or “near-fall” events—were unlikely to be captured, thereby limiting the comprehensiveness of the safety assessment. Incorporating patient-reported outcomes or nursing documentation could provide a more complete picture of the risk spectrum. The study also relied entirely on electronic health records and pharmacy dispensing data to define exposure and outcomes. While pragmatic, this approach may overlook critical factors such as medication adherence, dose adjustments, and the use of over-the-counter agents, all of which substantially influence drug safety [3]. Without validating dispensing records against actual drug consumption, residual misclassification remains a concern. In conclusion, George et al. provide valuable evidence supporting caution in the prescribing of baclofen and tizanidine among older adults. Nonetheless, the exclusion of frail patients, the narrow focus on major injuries, and reliance on dispensing data alone may underestimate the true risks in real-world geriatric care. Addressing these gaps in future studies will be essential to ensure that prescribing recommendations are both rigorous and generalizable to the most vulnerable populations who bear the greatest burden of adverse drug events. Yarong Li: writing – original draft. Jing Han: conceptualization. Liming Lou: supervision, writing – review and editing. The authors have nothing to report. The authors declare no conflicts of interest. This publication is linked to a related Letter to the Editor by George and Deamer. To view this article, visit https://doi.org/10.1111/jgs.70220. The authors have nothing to report.