Gabapentin is an FDA-approved prescription anticonvulsant that is primarily used to treat nerve pain and control epileptic seizures. But it is also prescribed “off-label” as a painkiller or treatment for fibromyalgia, sciatica, insomnia, anxiety, hot flashes, and lower back pain. It’s a popular choice since it’s not as addictive as opioids. Like all medications, gabapentin has potential side effects such as nausea, dizziness, tiredness, headaches, memory loss, and difficulty speaking. However, a new study found that people who took six or more prescriptions of gabapentin for lower back pain are at a higher risk of mild cognitive impairment and dementia.
Gabapentin side effects may include dementia?
The study was published in the journal Regional Anesthesia & Pain Medicine and involved data from the federated health research network TriNetX. The researchers examined information of over 26,000 adults diagnosed with chronic pain, chronic pain syndrome, chronic lower back pain, or lumbar radiculopathy. They compared this data to an equally sized group that doesn’t take the drug. Then they separated the participants into five age groups: 18–64, 18–34, 35–49, 50–64, and 65+. After that, they analyzed the outcomes a decade later to see how many developed mild cognitive impairment (MCI), Alzheimer’s disease, or vascular dementia.
“Currently, there is a discrepancy on whether taking gabapentin increases a patient’s risk for developing dementia,” said Nafis B. Eghrari, first author of the study, and a 4th-year medical student at Case Western Reserve University School of Medicine, to Medical News Today. “Moreover, there lacks a strong understanding of how gabapentin impacts cognitive function and whether it contributes to neurodegenerative processes. Previous studies have shown mixed findings on this topic. Thus, we decided to explore this gap in the field.”
The study concluded that participants who had six or more prescriptions of gabapentin had a 29% increased risk of developing dementia, and 85% increased risk of MCI. “The significance of this finding is an association between gabapentin prescription and dementia on a nationwide level,” said Eghrari. “Though this does not imply causation, this warrants further investigation on the drug’s long-term effects.”
Furthermore, the team found that the risk was higher for the age group of 35–49. In fact, the risk of dementia is double for them, and triple for MCI. Eghrari explained that they were surprised that the increased risk came from this non-elderly population. Keep in mind, people in general are at higher risk of neurodegeneration after 65 years of age.
The study’s limitations and criticisms
This observational study does have some drawbacks to keep in mind. One is that there is little to no information provided about participants having other diagnoses or taking other medications. Plus, there are so many variables when it comes to dementia risk. Therefore, it’s impossible to establish the exact cause, especially in studies using large data sets. “One very important factor that was not examined in this study is levels of physical activity,” said Tara Spires-Jones, director of the Centre for Discovery Brain Sciences at the University of Edinburgh, to Medscape. “People with chronic pain requiring gabapentin may have been less physically active, which is a known risk factor for developing dementia.”
Meanwhile, Ian Maidment, professor in clinical pharmacy, Aston University, Birmingham, England, pointed out the analysis did not control for length of treatment or dosages. He noted that “other similar recent studies have failed to find a link.” Therefore, he believes “the jury is out on whether gabapentin causes dementia.”
Neel Anand, MD, MCh Orth, a board-certified orthopedic spine surgeon, who was not involved in the study, said the best way to prove causation is to compare participants who take the specific drug (and nothing else) to those who don’t take it. Additionally, the researchers must confirm the medication is taken as directed. Nevertheless, Anand says that “at least we can be cognizant” about the potential dementia side effect of extended gabapentin use.
Main takeaways
Despite the caveats of an observational study, the authors recommend vigilance when taking this drug. “In terms of clinical significance, I recommend that physicians prescribing gabapentin for chronic pain perform cognitive exams on a regular basis when seeing patients,” said Eghrari. He also says doctors should be cautious overall when prescribing it. “I’d also advise patients who are taking this drug to alert their physician if they notice any cognitive deficits, including confusion, poor memory, or slowed thinking.”
Other serious side effects to look out for are allergic reactions, mood or behavioral changes, suicidal ideation, jaundice, and bloody urine, according to Cleveland Clinic. People who take gabapentin should consult their doctor if they have any concerns. They should not stop taking it or change their dose without professional guidance. Going off cold turkey can lead to complications like an increased risk of seizures for those taking it for epilepsy.
Eghrari concluded: “We hope to carry this research forward and explore whether there is a true causative relationship between gabapentin and cognitive impairment. We also plan to investigate the underlying mechanisms of how the drug may impact cognition.”
