Donepezil Shows Promise in TBI Recovery

TOPLINE:

Donepezil was associated with improved verbal memory and enhanced recall and processing speed compared to placebo in patients with severe traumatic brain injury (TBI), with a favorable safety profile despite mild to moderate gastrointestinal side effects.

METHODOLOGY:

• A four-site, randomized, parallel-group, double-blind, placebo-controlled, 10-week clinical trial (MEMRI-TBI-D) was conducted between 2013 and 2019 to evaluate the efficacy of donepezil for verbal memory impairments following severe TBI.
• 75 adults (75% men; mean age, 37 years) with complicated mild, moderate, or severe nonpenetrating TBI at least 6 months prior to study participation were included and randomly assigned to receive donepezil (n = 37) or placebo (n = 38).
• Participants received 5 mg donepezil daily or matching placebo for 2 weeks, then donepezil at 10 mg daily or matching placebo for 8 weeks; treatment was discontinued at 10 weeks, with an additional 4-week observation period.
• Verbal memory was assessed using the Hopkins Verbal Learning Test–Revised (HVLT-R). The primary outcome measure was verbal learning, evaluated through the HVLT-R total recall (ie, Total Trials 1-3) score.

TAKEAWAY:

• Compared with placebo, donepezil was associated with significantly greater improvements in verbal learning in both modified intent-to-treat and per-protocol analyses (P = .034 and .036, respectively).
• Treatment-responder rates were significantly higher in the donepezil group than in the placebo group (42 vs 18%; P = .03), with donepezil responders showing significant improvements in delayed recall and processing speed.
• Although there were no serious adverse events in either group, treatment-emergent adverse events were significantly more common in the donepezil group vs placebo (46% vs 8%; P
• Diarrhea and nausea were significantly more common in the donepezil group than in the placebo group (Fisher’s exact test: diarrhea, P = .03; nausea, P = .01).

IN PRACTICE:

“This study demonstrates the efficacy of donepezil on severe, persistent verbal memory impairments after predominantly severe TBI, with significant benefit for a subset of persons with such injuries, as well as a relatively favorable safety and tolerability profile,” the investigators wrote.

SOURCE:

The study was led by David B. Arciniegas, MD, University of Colorado School of Medicine, Aurora, Colorado. It was published online on December 4 in The Journal of Neuropsychiatry and Clinical Neurosciences.

LIMITATIONS:

The study included a relatively small sample with predominantly severe TBI requiring hospitalization and inpatient rehabilitation. The sample characteristics limit the generalizability of the findings to persons with other severities of TBI, other types of memory impairments, or more complex neuropsychiatric presentations. The study population had an average of 14 years of education, making generalizability to individuals with lower education levels uncertain. Additionally, while measures of information processing speed and immediate auditory attention were included, specific measures of sustained or selective attention were not, making it difficult to rule out improvements in higher-level attention as potential contributors to the observed verbal memory performance improvements.

DISCLOSURES:

The study was funded by the National Institute on Disability, Independent Living, and Rehabilitation Research, with in-kind support from TIRR Memorial Hermann. Four authors disclosed various financial and professional affiliations, including advisory roles with pharmaceutical and diagnostic companies, support from institutional awards, and involvement in programs funded by external organizations. One author served as the editor of The Journal of Neuropsychiatry and Clinical Neurosciences, with an independent editor overseeing the review and publication process for this article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.