Gabapentin and pregabalin are two drugs marketed to treat some specific neurologic or psychiatric diseases. However, recent studies have shown that the prescription of these drugs is increasing, suggesting that these drugs could be prescribed to patients too readily, and for non-approved indications (off label-use). Recently, the UK government reclassified gabapentin and pregabalin as controlled substances, after safety warnings following an increase in deaths related to their use. In this context, it could be relevant to better understand the patterns in the use of these medications. For this purpose, we will describe the trends over time in the prescription of gabapentin and pregabalin in the UK primary care between 1993 and 2017. We will also classify the medical drug indication for each patient starting on gabapentin or pregabalin. The findings of our study are expected to inform physicians and public health decision makers about the levels of gabapentin and pregabalin prescriptions over time, especially for non-approved indications.
The gabapentinoid drugs gabapentin and pregabalin are approved treatments for focal seizures and neuropathic pain, and were licensed in the UK in 1993 and 2004, respectively. Gabapentin is also licenced for the treatment of migraine in adults, while pregabalin is approved for the treatment of generalized anxiety disorder. Recent data in the UK and elsewhere indicate that gabapentinoid prescriptions are increasing, raising concerns about potential off label-use of these drugs. Moreover, the UK government has recently reclassified these drugs as class C controlled substances, after an increasing number of deaths were found to be related to their use. Given these safety concerns and the implications of the widespread use of these medications, we will conduct a drug utilization study using CPRD data between January 1, 1993 and December 31, 2017. We will estimate annual prescription rates and 95% confidence intervals for gabapentin and pregabalin separately, using Poisson regression. We will also estimate the rates of incident users over time, both overall and stratified by indications and off-label indications. Our results will provide insight as to how gabapentinoids have been prescribed in UK primary care practices since their licensing and approval.
To estimate the yearly prescriptions rates of gabapentinoids (gabapentin and pregabalin, separately) in the UK primary care, between 1993 and 2017 in children, adolescents and adults;
To estimate the yearly rate of patients with a first gabapentinoid prescription (incident users) overall and stratified by indication (epilepsy, neuropathic pain/migraine, generalized anxiety disorder (only for pregabalin), non-neuropathic pain (off-label indication), and other off-label indications).
Samy Suissa - Chief Investigator - Sir Mortimer B Davis Jewish General Hospital
Christel Renoux - Corresponding Applicant - McGill University
Alvi Rahman - Collaborator - McGill University
Francois Montastruc - Collaborator - University Of Toulouse
Joseph Kane - Collaborator - Queen's University Belfast
Simone Loo - Collaborator - McGill University