Research project

Understanding the impact of the national change in gabapentinoid classification and the risk factors for serious harms

Project to look at the pain caused by nerve damage

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Start date

January 2023

Completion date

March 2024



National Institute of Academic Anaesthesia (British Journal of Anaesthesia/Royal College of Anaesthetists)

Nerve damage, such as from surgery or from diabetes, can cause a particular type of pain called neuropathic pain1. Standard painkillers, like paracetamol or ibuprofen, often don’t work well. Gabapentin and pregabalin (known as gabapentinoids) are medicines used as a first-choice treatment for neuropathic pain2-4. However, these medications are also used for other types of pain, without good evidence they work well.

Gabapentinoid prescribing is increasing in the UK5,6. This may be to avoid prescribing opioid painkillers, such as morphine7. Opioids have had a lot of negative publicity, with concerns about major risks such as addiction, overdose and death. In comparison, there has been little research around gabapentinoids and related serious harms. However, between 2012 and 2017, deaths where gabapentinoids were implicated increased 10-fold in Scotland8. The increase in gabapentinoid-related deaths (GRDs) is similar to the increase in prescribing rates9.

In response to the rise in GRDs, the UK government reclassified both gabapentin and pregabalin as controlled substances in April 201910. This introduced tighter regulation around their supply. This was expected to prompt prescribers to consider the risks of gabapentinoids, thus reducing GRDs. However, it is unclear how effective the reclassification has been, as there are few alternatives to gabapentinoids, and the drugs may increasingly be obtained illicitly.

Drug-related deaths in Scotland reached a record high in 20208, with Tayside being one of the worst affected areas. Therefore, there is an urgent need for effective clinical guidelines and policies based on reliable research.

This study aims to investigate:

  1. The impact of the UK government reclassification of gabapentinoids on prescribing rates and their related harms.
  2. The risk factors that are associated with gabapentinoid-related harms.

 We will study existing data on gabapentinoid-related outcomes, including prescribing and serious harms. We will analyse:

  1. Trends in gabapentinoid prescribing and death rates, before and after reclassification in Scotland. These will be compared to similar data from England, Wales, and Northern Ireland.
  2. Trends in gabapentinoid non-fatal overdose (NFOD) and misuse rates in NHS Tayside and neighbouring NHS Fife before and after reclassification.
  3. By linking this data with other routinely collected clinical datasets, we will identify risk factors for GRDs, NFOD and misuse in people being treated with gabapentinoids. This will be done using appropriate data protection and management, working with the expert team in the Health Informatic Centre, University of Dundee.

We will understand how UK Government reclassification has affected gabapentinoid prescribing and GRD rates across the UK as well as gabapentinoid NFOD and misuse locally that have occurred since. We will also uncover risk factors that are associated with these harmful outcomes. 

Ultimately this study will help to inform clinical policy and guidelines to promote safe and effective prescribing of gabapentinoids in treating conditions such as neuropathic pain. It will also contribute to further planned research into the development of a clinical tool to help doctors predict serious negative outcomes in patients being considered for gabapentinoid treatment.



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  1. Colloca L, Ludman T, Bouhassira D, et al. Neuropathic pain. Nat Rev Dis Prim 2017; 3: 17002
  2. Scottish Intercollegiate Guideline Network. SIGN 136: Management of chronic pain: A national clinical guideline [revised edition]. Edinburgh; 2019 Available from:
  3. National Institute for Health and Care Excellence. Neuropathic pain in adults: pharmacological management in non-specialist settings. 2013 Available from:
  4. Finnerup NB, Attal N, Haroutounian S, et al. Pharmacotherapy for neuropathic pain in adults: A systematic review and meta-analysis. Lancet Neurol 2015; 14: 162–73
  5. Montastruc F, Loo SY, Renoux C. Trends in First Gabapentin and Pregabalin Prescriptions in Primary Care in the United Kingdom, 1993-2017. JAMA 2018; 320: 2149–51
  6. Torrance N, Veluchamy A, Zhou Y, et al. Trends in gabapentinoid prescribing, co-prescribing of opioids and benzodiazepines, and associated deaths in Scotland. Br J Anaesth 2020; 125: 159–67
  7. Hébert HL, Morales DR, Torrance N, Smith BH, Colvin LA. Assessing the impact of a national clinical guideline for the management of chronic pain on opioid prescribing rates: a controlled interrupted time series analysis. Implement Sci 2022; 17: 77
  8. National Records of Scotland. Drug-related Deaths in Scotland in 2020. 2021. Available from:
  9. Lyndon A, Audrey S, Wells C, et al. Risk to heroin users of poly-drug use of pregabalin or gabapentin. Addiction 2017; 112: 1580
  10. Iacobucci G. UK government to reclassify pregabalin and gabapentin after rise in deaths. BMJ 2017; 358: j4441

Project type

Research project