Risk of Injury, Delirium Greater With Baclofen Than Tizanidine for Older Adults

Compared to tizanidine, baclofen was associated with a higher incidence of injury and delirium in older adults, according to findings published in the Journal of the American Geriatrics Society.

“Baclofen and tizanidine are both muscle relaxants that carry the risk for neuropsychiatric events in older adults but there is a lack of data directly comparing their safety,” researchers said. 

The retrospective cohort study was conducted in an integrated health care system in the United States. Patients were included if they were at least 65 years of age and initiated baclofen or tizanidine for musculoskeletal pain from January 2016 through December 2018.

Researchers followed the patients from the start of therapy until the end of the index drug exposure, end of health plan membership, death, or the study period’s end date which was December 31, 2019.

The study involved 12,101 patients receiving baclofen and 6027 patients receiving tizanidine. Patients were an average age of 72.2 ± 6.2 years, and 59% of the cohort was female, researchers reported.

Compared to patients taking tizanidine, those who initiated baclofen experienced higher rates of delirium (HR = 3.33, 95% CI 2.11 to 5.26, P < .001) and injury (HR = 1.54, 95% CI 1.21 to 1.96, P < .001), which included concussions, contusions, dislocations, falls, fractures, and other injuries.

“Future studies should investigate if these risks are dose-related and include a comparison group not exposed to either drug,” researchers advised.

Reference:
Su Zhang VR, Niu F, Lee EA, et al. Safety of baclofen versus tizanidine for older adults with musculoskeletal pain. J Am Geriatr Soc. Published online March 29, 2023. doi:10.1111/jgs.18349