UCL Researchers Uncover Critical Risks in Gabapentinoid Prescribing

A groundbreaking study from University College London (UCL) has shed new light on the dangers associated with gabapentinoids, a class of medications commonly prescribed for neuropathic pain, epilepsy, and anxiety disorders. Led by experts at UCL's School of Pharmacy, the research reveals that patients taking these drugs face a significantly heightened risk of drug poisoning, particularly when combined with opioids or benzodiazepines. This finding, published in PLOS Medicine, underscores the need for greater caution in clinical practice across European healthcare systems.

Gabapentin (brand name Neurontin) and pregabalin (Lyrica) have seen a sharp rise in use over the past decade, driven by their effectiveness in managing chronic conditions. In the UK alone, millions of prescriptions are issued annually, with similar trends observed in countries like France and Denmark. However, the UCL study highlights how these benefits come with substantial safety concerns, prompting calls for enhanced monitoring and prescribing guidelines from university-led research initiatives.

Understanding Gabapentinoids: From Therapeutic Promise to Hidden Dangers

Gabapentinoids work by mimicking the neurotransmitter gamma-aminobutyric acid (GABA), calming overactive nerve signals to alleviate pain and seizures. First approved in the 1990s, their off-label use for anxiety and fibromyalgia has surged, making them one of the most prescribed drug classes in Europe. Yet, as UCL researchers note, their sedative properties can lead to respiratory depression and central nervous system suppression, especially in vulnerable populations such as the elderly or those with comorbidities.

European universities have long tracked these trends. For instance, studies from Aston University in Birmingham and the University of Hong Kong (with UCL collaborations) show prescribing rates doubling in the UK between 2010 and 2020. In France, pregabalin sales climbed steadily until regulatory tweaks in 2021. This widespread adoption has fueled research at institutions like UCL, where pharmacoepidemiologists use large datasets to quantify real-world risks.

The Methodology Behind UCL's Rigorous Analysis

The UCL team employed a self-controlled case series (SCCS) design, analyzing data from the UK's Clinical Practice Research Datalink (CPRD) Aurum database, linked to Hospital Episode Statistics (HES) and Office for National Statistics (ONS) mortality records. This covered over 16,800 patients aged 18 and older who experienced an incident drug poisoning event between 2010 and 2020 after starting gabapentinoids.

By using patients as their own controls, the study minimized confounding factors like genetics or lifestyle. Risk periods were divided into pre-treatment (90 days before), early treatment (first 28 days), mid-treatment (29-84 days), and ongoing treatment. Adjustments accounted for age, season, and concomitant medications like opioids, antiseizure drugs, psychotropics, and NSAIDs. A complementary case-case-time-control (CCTC) analysis validated results, confirming elevated odds of recent gabapentinoid exposure before poisoning events.

This sophisticated approach, honed at UCL's Research Department of Practice and Policy, exemplifies how European academic centers leverage linked health data for impactful pharmacovigilance.

Key Findings: Elevated Poisoning Risks Across Treatment Phases

The study found the risk of hospitalization for drug poisoning was more than doubled in the 90 days before starting gabapentinoids (adjusted incidence rate ratio [aIRR] 2.09, 95% CI 1.98-2.21), likely reflecting prescribers selecting higher-risk patients. Upon initiation, the risk remained high in the first 28 days (aIRR 1.81, 95% CI 1.66-1.99), gradually declining but staying elevated throughout treatment (aIRR 1.11 for remaining period).

• No significant difference between gabapentin and pregabalin.
• 89% of patients had prior opioid or psychotropic prescriptions.
• Patient profile: 53.5% female, mean age 47, 83.7% with neuropathic pain, 76.2% mental health conditions.

These patterns suggest an inherent vulnerability during treatment initiation, a critical insight for pharmacy educators training future clinicians at universities like UCL and beyond.

Dangerous Synergies: Interactions with Opioids and Benzodiazepines

The most alarming results concerned polydrug use. Combining gabapentinoids with opioids increased poisoning risk by up to 30% overall, reaching aIRR 2.14 in the first 28 days. Benzodiazepines doubled the risk (aIRR up to 3.95), likely due to synergistic central nervous system depression leading to respiratory failure.

European research echoes this; a Danish cohort study reported gabapentinoid prevalence rising fourfold to 41 per 1,000 adults by 2023, often co-prescribed with opioids. UCL lead author Dr. Kenneth Man emphasized, "Clinicians should be cautious, especially with concurrent opioids or benzodiazepines, and monitor patients closely."

Implications for Clinical Practice and Patient Safety in Europe

UCL's findings urge revised prescribing protocols. In the UK, gabapentinoids are Schedule 3 controlled drugs since 2019, yet incidents persist. The study recommends starting low doses, frequent reviews, and avoiding combinations where possible. For Europe, where pregabalin consumption rose 17% annually per global trends, universities like those in France (where sales peaked pre-2021 reforms) are pivotal in disseminating guidelines.

Patient education is key: symptoms like drowsiness, confusion, and breathing difficulties signal overdose. European Medical Agency (EMA) warnings align, noting misuse potential. UCL's Centre for Medicines Optimisation Research advocates shared decision-making to balance benefits against risks.

UCL School of Pharmacy: Leading Europe's Pharmacovigilance Efforts

UCL's School of Pharmacy, ranked top globally, spearheads such studies through its pharmacoepidemiology expertise. Collaborations with Aston University and Hong Kong University enhance multinational insights. This research builds on prior UCL work, like 2025 self-harm analyses, positioning the institution as a hub for drug safety innovation.

European counterparts, including Denmark's University of Southern Denmark tracking fourfold prescribing increases, contribute to continent-wide surveillance. Funding from UCL Hospitals NHS Trust ensures translation to policy, benefiting pharmacy curricula across the UK and EU.

Broader Public Health and Policy Ramifications Across Europe

With gabapentinoids linked to 25% of UK drug-related deaths involving opioids, the study amplifies calls for tighter controls. France saw pregabalin high-dose use at 26 per 1,000 person-years; Denmark 41 per 1,000 adults. UCL urges registries for monitoring, akin to opioid programs.

Stakeholders: NICE guidelines may update; EMA reviews ongoing. For universities, it highlights interdisciplinary research—pharmacy, psychiatry, epidemiology—fostering safer prescribing education.

Stakeholder Perspectives and Real-World Case Insights

Dr. Man (UCL): "Risk peaks early; polydrug use is dangerous." Patient advocates note underreported overdoses in primary care. A UK case series showed 60% unintentional exposures, 28% suicides among older gabapentin users.

• Clinicians: Dose titration, screen for co-morbidities.
• Regulators: Enhanced warnings, yellow card reporting.
• Patients: Report side effects promptly.

European universities like those in Birmingham emphasize deprescribing strategies in curricula.

Future Research Directions from European Academic Centers

UCL plans longitudinal studies on long-term risks, adherence. Collaborations with EU partners target mechanistic insights into interactions. Emerging: genetic factors influencing susceptibility, per Danish cohorts.

Actionable insights: AI-driven risk prediction tools, pharmacy-led interventions. As gabapentinoid use grows, university research remains vital for evidence-based policy.

Photo by Etactics Inc on Unsplash

Conclusion: Advancing Safer Medication Practices Through University Research

UCL's study is a wake-up call for European healthcare, blending rigorous data with practical recommendations. By highlighting interaction risks, it empowers universities to train safer prescribers, ultimately protecting patients continent-wide. Ongoing vigilance from academia will shape future guidelines.