Project Summary/Abstract
Gabapentin, currently approved to treat partial seizures and postherpetic neuralgia, was
the 6th most commonly prescribed medication in the US in 2018. Notably, close to 95% of gabapentin
prescriptions are for off-label indications, such as neuropathic pain, migraines, substance use disorder, and
psychiatric symptoms. Gabapentin's widespread use may be driven by a belief that it is a safer drug than
opioids and antipsychotics. However, there is an increasing concern about the safety of gabapentin use, and
several studies have reported that gabapentin has the potential for misuse and abuse. In particular, although
gabapentin prescription has dramatically increased in older adults, our understanding of gabapentin use in this
population is limited. Due to gabapentin's known binding site, alpha-2-delta-1, which has a relationship with
calcium channel, NMDA receptor, and thrombospondin, it is possible that gabapentin could affect older adults'
cognition and motor functions. To fill in the research gap, this study proposes to assess longitudinal patterns of
gabapentin use in older adults and to estimate the risk of health-related outcomes associated with gabapentin
prescriptions using Medicare claims data and linked Rush Alzheimer Disease Center-Medicare data. Aim 1 will
determine the distinct patterns (e.g., duration of use, concurrent medications, history of medication prior to
gabapentin initiation) of gabapentin use and examine the factors, including demographics and medical history,
associated with each pattern. This aim will provide clinically relevant characteristics of gabapentin users to
further investigate. Aim 2 will examine the association of gabapentin use with health-related outcomes,
including falls, fractures, neurocognitive changes, hospitalizations, emergency department visits, and mortality.
These associations will be estimated marginal structural models by considering time-varying exposure patterns
and time-varying confounders, including concurrent use of other medications and medical history. This
proposal fits into the National Institute on Aging's special interest of research on pain, pain management, and
opioids in aging.
Through completing this project, Dr. Oh will gain experience in real-world evidence studies and expand
her toolbox to serve her professional future as a neuro-pharmacoepidemiologist. Since medication use and its
effects is highly influenced by policy, this project will build Dr. Oh's knowledge of the process of translating
research into policy. Lastly, Dr. Oh will sharpen essential professional skills, such as grant writing, networking,
and mentoring. She will be guided by a strong interdisciplinary mentoring team with collective expertise in
neuroepidemiology, pharmacoepidemiology, health-related outcomes, policy, and biomedical informatics.
Findings from this study will help healthcare providers and policymakers better understand the risks and
benefits of prescribing gabapentin to older adults and will provide the baseline knowledge for further
investigation into establishing the causal relationship between gabapentin and health-related outcomes.