# A novel multimodal pharmacologic approach using guanfacine, N-acetylcysteine, and donepezil in severe TBI: a case series

**Authors:** Arman Fesharaki-Zadeh, Timothy Belliveau, Robert H. Pietrzak, Amy Arnsten

PMC · DOI: 10.3389/fresc.2025.1648002 · Frontiers in Rehabilitation Sciences · 2025-10-24

## TL;DR

This case series explores a new drug combination to improve cognitive function in severe traumatic brain injury patients.

## Contribution

A novel multimodal pharmacologic approach using guanfacine, NAC, and donepezil for severe TBI is proposed and evaluated.

## Key findings

- The GND regimen showed encouraging cognitive improvements in TBI patients.
- The combination targets multiple neurochemical pathways disrupted by TBI.
- Preliminary results suggest potential for mitigating chronic cognitive issues in TBI.

## Abstract

Traumatic brain injury (TBI) remains a leading cause of long-term morbidity and disability worldwide. Individuals with moderate to severe TBI often experience persistent neurocognitive deficits, including short-term memory loss, executive dysfunction, and slowed cognitive processing for which there are currently no FDA-approved treatments. This case series investigates the synergistic use of guanfacine, N-acetylcysteine (NAC), and donepezil (GND) administered alongside ongoing cognitive rehabilitation, with treatment effects evaluated through pre- and post-intervention Montreal Cognitive Assessment (MoCA) scores. The guanfacine/NAC combination has previously been reported to improve working memory and executive function in individuals with mild TBI, suggesting its potential applicability to more severe TBI cases. Guanfacine, an alpha-2A agonist approved for ADHD, enhances prefrontal cortical function; Donepezil, a cholinesterase inhibitor, is widely used to treat cognitive symptoms in mild cognitive impairment and early dementia; and NAC, a potent antioxidant and glutamate modulator, has demonstrated neuroprotective effects across a range of clinical contexts, including TBI. Each of these agents has a well-established safety profile. The encouraging outcomes observed in this case series underscore the potential of the GND regimen as a multimodal pharmacologic approach to target the complex neurochemical disruptions following TBI. These preliminary findings warrant further investigation in larger, placebo-controlled trials in order to more rigorously assess the safety, efficacy, and translational potential of this intervention for mitigating chronic cognitive sequelae in individuals with moderate to severe TBI.

## Linked entities

- **Chemicals:** guanfacine (PubChem CID 3519), N-acetylcysteine (PubChem CID 12035), donepezil (PubChem CID 3152)
- **Diseases:** traumatic brain injury (MONDO:0858950), ADHD (MONDO:0007743), dementia (MONDO:0001627)

## Full-text entities

- **Genes:** BCHE (butyrylcholinesterase) [NCBI Gene 590] {aka BCHED, CHE1, CHE2, E1}, IGKV2D-29 (immunoglobulin kappa variable 2D-29) [NCBI Gene 28882] {aka A2a, A2c, IGKV2D29}
- **Diseases:** executive dysfunction (MESH:D006331), TBI (MESH:D000070642), neurocognitive deficits (MESH:D009461), dementia (MESH:D003704), ADHD (MESH:D001289), cognitive impairment (MESH:D003072), cognitive symptoms (MESH:D019954), memory loss (MESH:D008569)
- **Chemicals:** GND (-), Guanfacine (MESH:D016316), N-acetylcysteine (MESH:D000111), glutamate (MESH:D018698), Donepezil (MESH:D000077265)

## Full text

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## Figures

4 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12592045/full.md

## References

60 references — full list in the complete paper: https://tomesphere.com/paper/PMC12592045/full.md

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Source: https://tomesphere.com/paper/PMC12592045