• Keele researchers have found a link between patients prescribed gabapentinoids and a greater risk of ‘adverse events’ such as drug misuse, overdose, and major trauma such as a bone fracture or head injury.   

• The researchers looked at anonymised GP records to compare rates of adverse events in patients who were prescribed gabapentin or pregabalin therapeutically by their doctor, with those who were not.  

• Adverse events in patients prescribed gabapentinoids were more likely if they were a smoker, had a history of substance misuse, overdose, or a mental health condition, and if they were also prescribed other drugs that affect the central nervous system. 

Risk of adverse effects 

Doctors and clinicians must exercise extreme caution when selecting patients to prescribe gabapentinoids to, Keele researchers have said, after finding a link between gabapentinoid prescriptions and a higher risk of worse outcomes for patients. 

Gabapentinoids such as gabapentin and pregabalin are anticonvulsant drugs that are approved in the United Kingdom and EU to treat epilepsy, neuropathic pain, and, in the case of pregabalin, generalised anxiety disorder.   

The new study, published in the journal Pain, identified higher rates of drug misuse, overdose, and major trauma such as a bone fracture or head injury in patients prescribed gabapentinoids by a healthcare professional, compared with those who were not. 

Identifying risks to patients  

This research studied the risks for people who were legitimately prescribed gabapentinoids by their doctor in UK primary care and contributes to the growing body of evidence regarding the potential harms of these drugs.  

The researchers looked at anonymised GP records to compare rates of “adverse events” like substance misuse, overdose, and major injury, in patients who were prescribed gabapentinoids versus those who were not, and found these events were more common among patients who were prescribed these medicines.  

The findings, published in the journal Pain, also showed that patients prescribed gabapentinoids were at higher risk of these events if they were a smoker, had a history of substance misuse, overdose, or a mental health condition, and if they were also prescribed other drugs that affect the central nervous system. 

“Careful patient selection” needed 

When they were first introduced, gabapentinoids were thought to be safe medicines with no risk of addiction, but they were reclassified in 2019 due to the potential for misuse or harm.  

At that time, most harms reported from gabapentinoids were in more high-risk groups including opioid addicts. Most gabapentinoid-related deaths involve other psychoactive and sedative drugs, with up to 90% also involving opioids.  

Chief Investigator Dr Julie Ashworth, Senior Lecturer and Honorary Consultant in Pain Medicine at Keele, said: “This study highlights the importance of careful patient selection when prescribing gabapentinoids.  

“These drugs only benefit a small proportion of patients with clearly defined nerve pain and do not help with other types of chronic pain. Prescribers need to be aware that patients who take other medication for pain, such as opioids and antidepressants, are at increased risk of gabapentinoid-related harm.”