Gabapentin and Pregabalin Raise Poisoning Risk Sharply in First Weeks of Use
A UK study of 17,000 patients found gabapentinoid users face nearly double the drug poisoning risk early in treatment, especially combined with opioids or benzodiazepines.
Summary
Gabapentin and pregabalin — two widely prescribed pain medications — significantly raise the risk of drug poisoning hospitalization in the first four weeks of use, according to a large UK study. Researchers analyzed over 16,000 patients and found the risk was nearly twice as high shortly after starting these drugs compared to other periods. When combined with benzodiazepines, the risk quadrupled; with opioids, it doubled. Despite being marketed as safer alternatives to opioids, these drugs carry real dangers, particularly when used alongside other central nervous system depressants. The findings are especially relevant given that gabapentin was the fifth most dispensed drug in US pharmacies in 2024.
Detailed Summary
Gabapentinoids — the drug class that includes gabapentin and pregabalin — are among the most commonly prescribed medications in the US and UK, often used off-label for chronic pain. A new large-scale study published in PLoS Medicine challenges the assumption that these drugs are a straightforwardly safe alternative to opioids, revealing significant poisoning risks concentrated in the early weeks of treatment.
Researchers at University College London analyzed data from over 1.35 million UK primary care patients prescribed gabapentinoids between 2010 and 2020. Of those, 16,827 experienced at least one drug poisoning hospitalization. Using a self-controlled case series design — which compares each patient to themselves across different time periods — the team found that poisoning risk was 81% higher in the first four weeks of gabapentinoid treatment compared to reference periods.
The risk escalated dramatically with co-prescriptions. Patients taking gabapentinoids alongside benzodiazepines were nearly four times more likely to be hospitalized for drug poisoning in those critical first weeks. Those combining gabapentinoids with opioids faced double the risk. These combinations are common: 89% of study participants had been prescribed opioids alongside gabapentinoids at some point, and over half had concurrent benzodiazepine prescriptions.
For health-conscious individuals and patients managing chronic pain, these findings carry clear practical weight. The early treatment window appears to be a period of heightened vulnerability, suggesting that closer monitoring, lower starting doses, and careful review of concurrent medications could reduce harm. Clinicians should be especially cautious when initiating gabapentinoids in patients already on CNS depressants.
Important caveats apply. The study population had high rates of mental health conditions and chronic pain, and intentional poisonings were included alongside accidental ones, which may inflate risk estimates for typical patients. The UK setting and specific patient demographics may also limit direct generalizability to other populations.
Key Findings
- Gabapentinoid users had 81% higher drug poisoning hospitalization risk in the first 4 weeks of treatment.
- Combining gabapentinoids with benzodiazepines nearly quadrupled early poisoning risk (aIRR 3.95).
- Adding opioids to gabapentinoids doubled poisoning hospitalization risk in the first month.
- 89% of study participants were co-prescribed opioids alongside gabapentinoids at some point.
- Gabapentin was the fifth most dispensed drug in US retail pharmacies in 2024, highlighting broad public exposure.
Methodology
This is a news report summarizing a peer-reviewed study published in PLoS Medicine, a credible open-access journal. The study used a self-controlled case series design on 16,827 UK patients from a validated primary care database (CPRD Aurum), which controls for fixed confounders by comparing individuals to themselves across time periods.
Study Limitations
The study included both intentional and accidental poisonings, which may overestimate risk for patients using medications as directed. The population had high rates of mental health conditions and chronic pain, limiting generalizability to healthier adults. UK prescribing patterns and healthcare context may differ from US or other settings.
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