GABAPENTIN FOR BEHAVIORAL AND PSYCHIATRIC SYMPTOMS OF DEMENTIA: RENEWING THE CALL FOR AN INTERVENTION STUDY

Introduction Behavioral and Psychiatric Symptoms of Dementia (BPSD) increase patient mortality, healthcare costs and caregiver burnout. While behavioral interventions are the most effective treatment for BPSD, many patients are not able to regulate their agitation using only behavioral interventions, and therefore require pharmacotherapy. Various agents such as risperidone, quetiapine and trazodone have shown positive data for treating both BPSD and decreasing related caregiver burnout, but many of these agents are associated with significant increases in morbidity and mortality, as well as intolerable side effects. Several case reports describe using gabapentin, an anti-epileptic and FDA-approved treatment for neuropathic pain, as an off-label treatment for BPSD. BPSD in some patients may be driven by unreported neuropathic pain, which gabapentin can treat effectively. Additionally, gabapentin has known anxiolytic properties that can theoretically improve BPSD. A 2018 systematic review by Supasitthumrong et al highlights data supporting the use of gabapentin as a treatment for BPSD, but noted there has yet to be a definitive trial establishing gabapentin as an effective intervention for BPSD. We delineate two cases of patients with BPSD who were treated with gabapentin to highlight the need for a randomized controlled trial so that guidelines can be established for the treatment of BPSD with gabapentin. Methods Approximately 3000 CL psychiatry consultations placed between March 2017-May 2019 for patients admitted to the inpatient medicine service at the West Roxbury VA Medical Center in West Roxbury, MA, were reviewed. In the first round of screening, records were filtered based on patient problem lists for the presence of a neurocognitive disorder, any chronic pain condition and prescription of gabapentin. Seventy-one patients met criteria based on the initial screening. In the second round of review, records were further filtered for the utilization of gabapentin for the treatment of BPSD. Two patients met these criteria and the cases were further reviewed for psychiatry recommendations, as-needed behavioral medication utilization, behavioral scales and behavioral reports. Results The first case is an 82-year-old male with Alzheimer's dementia, who had unsatisfactory treatment of agitation with trazodone and quetiapine 25mg twice daily. Subsequently, for over a month, he was treated with gabapentin on a gradual dose increase from 100mg twice daily to three times daily. A favorable sustained response was achieved as no additional as needed medications for agitation were required and the patient scored well on both Cohen-Mansfield Agitation Inventory (6/14) and Rating Anxiety in Dementia Scale (6). Following this intervention, subsequent episodes of agitation were limited to delirium, especially during UTIs. The second case is a 97-year-old male with mixed Alzheimer's and vascular dementia who continued to have breakthrough agitation despite being treated with trazodone 25mg nightly. He was started on gabapentin 200mg daily for three weeks, in the setting of a fall that resulted in a wrist injury. After this intervention, he continued to require quetiapine at doses up to 25mg daily, as well as haloperidol at doses up to 7mg daily to manage breakthrough agitation. This behavioral pattern and intervention lasted for three weeks until the patient's BPSD was stabilized and he was discharged to an acute rehabilitation facility. Conclusions In the two cases presented, treating BPSD with gabapentin resulted in mixed findings. While the first case shows gabapentin as a potentially efficacious and well-tolerated treatment for BPSD, it is difficult to elucidate the role gabapentin played in the second patient's improved behavioral regulation. There are many potential factors that may contribute to these discrepant findings. The first patient with Alzheimer's Dementia was followed for months while the second patient with mixed dementia patient was only followed for three weeks. Next, it is unclear whether gabapentin is equally efficacious in Alzheimer's dementia versus concomitant Alzheimer's and vascular dementia. Additionally, the age difference of 17?years may have also contributed to the 97-year old's limited response to gabapentin. Also, the first patient received a total gabapentin dose of 300mg while the second patient received 200mg. Lastly, the second patient presented in the context of pain due to a fall while the first patient did not. This case series magnifies the challenges of using gabapentin for BPSD without specific indications or established dosing recommendations. While gabapentin may be an effective treatment for BPSD, we present these cases to highlight the need for an interventional randomized controlled trial investigating gabapentin as a treatment for BPSD. This research was funded by: None