Gabapentin Dementia Lawsuit

From the record

When researchers analyzed a large insurance claims database tracking gabapentin prescriptions and neurological diagnoses over multiple years, they found a dose-dependent signal that no manufacturer-sponsored study had ever looked for. Patients who filled six or more gabapentin prescriptions had a 29% increased risk of developing dementia and an 85% increased risk of mild cognitive impairment compared to matched controls who never used gabapentin. The study controlled for age, sex, comorbidities, and concurrent medication use. But the most startling finding came from the age-stratified analysis: adults aged 35 to 49 — an age group where dementia is exceedingly rare — experienced a doubling of dementia risk and a tripling of MCI risk. The dose-response relationship and biological plausibility (gabapentin's known mechanism of binding to brain calcium channels essential for memory) establish this as one of the most significant pharmaceutical safety findings of 2025.

From the record

When researchers broke down their cohort by age at gabapentin exposure, the findings for younger adults defied every assumption about drug-induced cognitive decline being primarily an elderly concern. Patients aged 35 to 49 who used gabapentin chronically experienced a 2x increased risk of dementia and a 3x increased risk of MCI compared to age-matched controls. These relative risk elevations were the highest of any age group in the study — higher than the 65+ cohort, where absolute dementia rates are naturally elevated. The finding suggests that gabapentin may be initiating neurodegenerative processes in brains that should be decades away from cognitive decline. For plaintiffs' attorneys, this sub-analysis demolishes the anticipated defense argument that gabapentin merely accelerates pre-existing age-related neurodegeneration.

From the record

Analysis of the FDA's Adverse Event Reporting System reveals a long trail of cognitive and neurological adverse events associated with gabapentin that accumulated over decades without triggering a labeling change. FAERS entries for gabapentin include reports of memory impairment, cognitive disorder, confusional state, dementia, and amnesia spanning the drug's entire post-market history. The volume of cognitive-related FAERS reports accelerated markedly after 2015, correlating with gabapentin prescribing volumes exceeding 50 million annually. What researchers found when they examined the FAERS signal-to-noise ratio was that cognitive and neurological adverse events for gabapentin were reported at rates significantly exceeding background expectations for a non-psychotropic medication — a signal that was present in the FDA's own database but was never acted upon through labeling requirements.

From the record

A systematic review published in BMJ Open aggregated cognitive outcome data from randomized controlled trials of gabapentin and pregabalin, finding consistent evidence of impaired cognitive performance across multiple domains including attention, processing speed, and verbal memory. What the reviewers discovered when they pooled data from trials that had measured cognitive endpoints as secondary outcomes was a pattern of statistically significant cognitive impairment that individual trials had been too small to detect or had downplayed as clinically insignificant dizziness or somnolence. The meta-analysis established that gabapentinoid-associated cognitive impairment is not idiosyncratic — it appears across patient populations, dosage ranges, and indications, consistent with a pharmacological class effect tied to the drugs' calcium channel mechanism.

From the record

A pharmacokinetic review published in Clinical Pharmacokinetics documented what clinicians had long suspected but manufacturers had never adequately communicated: gabapentin accumulates to significantly higher blood and brain concentrations in patients with any degree of renal impairment — a condition that affects the majority of patients over age 65. Because gabapentin is excreted 100% unchanged by the kidneys, any decline in glomerular filtration rate directly increases drug exposure. What researchers calculated was that a 75-year-old patient with age-appropriate renal function taking a standard 300mg three-times-daily regimen achieves steady-state gabapentin levels approximately 40-60% higher than a 40-year-old on the same dose. For patients with moderate chronic kidney disease (common in the elderly population that represents gabapentin's largest user base), levels can be 100-200% higher than intended. The prescribing information provides renal dosing adjustments but does not warn that even modest renal decline in elderly patients creates a significant dose-exposure gap.