Neuropathic pain (NP) is a major health burden, affecting 7-10% of the general population (1). Whilst a range of pharmacological treatments are recommended, including gabapentinoids, and some anti-depressants (2), recent studies have suggested that a significant proportion of patients are not receiving a recommended medication (3,4). To date, there has been no evaluation of whether guidelines for NP are being followed, nor who is most likely to receive a recommended medication.

To identify the patient factors that influence being prescribed a recommended medication, in patients with chronic NP.  

 

As part of the DOLORisk study, participants from Generation Scotland (n=7240; general population cohort) were re-phenotyped for NP and comorbidities through a questionnaire survey (5–7). Chronic NP was identified by a DN4 score of 3 or more in participants reporting pain of at least 3 months’ duration. Questionnaire data were electronically linked to routinely collected NHS prescribing data (May 2016-September 2017). Medications recommended for the treatment of NP (RxNP) were derived from NeuPSIG, National Institute for Health and Care Excellence and Scottish Intercollegiate Guideline Network (SIGN 136) guidelines(2,8,9). These were gabapentin, pregabalin, carbamazepine, amitriptyline, imipramine, nortriptyline, clomipramine, desipramine, duloxetine, venlafaxine, strong opioids (including tramadol), lidocaine and capsaicin patches, ketamine and botulinum toxin A. Weak opioids, nonsteroidal anti-inflammatories, rubefacients, antimigraine, paracetamol, nefopam and combinations were considered non-NP pain medications (RxNon-NP). People who had received a RxNP were compared to people who had only received a Rxnon-NP. Continuous variables were analysed using the Mann-Whitney test whilst categorical variables were analysed using the chi-squared test. Statistical significance was set at P < 0.05.

 

 

 

A total of 859 people had chronic NP with linkage to prescribing data (median age: 59 years, range: 24-94 years, 67.6% female and 96.5% Caucasian). Of those, 187 (21.8%) had received a RxNP, 138 (16.1%) had only received a Rxnon-NP (without a RxNP) and 534 (62.2%) had not received any of the study medications. The RxNP group had a significantly higher proportion of people with pain duration longer than 5 years, severe chronic pain, any pain in the hip, leg or knee and any widespread pain, pain caused by neuropathy and non-current alcohol drinkers than the Rxnon-NP only group. Furthermore, the RxNP group had scores indicating significantly greater depression, anxiety, sleep disturbance, and pain-related worrying, and worse health-related quality of life than the Rxnon-NP group. 

 

These results suggest the great majority of people with chronic NP in the general population were not currently prescribed a recommended NP medication, nor any of the other pain medications studied. These patients may have received other treatments, or have previously been on NP medications. Of those receiving a study medication, the most likely to be prescribed a recommended NP medication were those with worse NP in terms of increased duration, higher severity and lower health-related quality of life.  

 

Further work is needed to understand the reasons for the apparent disparity between current guidelines and practice in the treatment of NP. This is likely to involve prescriber factors as well as patient factors.   

1.          Van Hecke O, Austin SK, Khan RA, Smith BH, Torrance N. Neuropathic pain in the general population: A systematic review of epidemiological studies. Pain. 2014;155(4):654–62. 

2.          Finnerup NB, Attal N, Haroutounian S, McNicol E, Baron R, Dworkin RH, et al. Pharmacotherapy for neuropathic pain in adults: A systematic review and meta-analysis. Lancet Neurol. 2015;14(2):162–73. 

3.          Hall GC, Carroll D, Parry D, McQuay HJ. Epidemiology and treatment of neuropathic pain: the UK primary care perspective. Pain. 2006;122(1–2):156–62. 

4.          Hall GC, Morant S V., Carroll D, Gabriel ZL, McQuay HJ. An observational descriptive study of the epidemiology and treatment of neuropathic pain in a UK general population. BMC Fam Pract. 2013;14. 

5.          Smith BH, Campbell A, Linksted P, Fitzpatrick B, Jackson C, Kerr SM, et al. Cohort profile: Generation scotland: Scottish family health study (GS: SFHS). The study, its participants and their potential for genetic research on health and illness. Int J Epidemiol. 2013;42(3):689–700. 

6.          Hébert HL, Veluchamy A, Baskozos G, Fardo F, Van Ryckeghem DML, Pascal MM V., et al. Cohort profile: DOLORisk Dundee: a longitudinal study of chronic neuropathic pain. BMJ Open. 2021;11(5):e042887. 

7.          Pascal MMV, Themistocleous AC, Baron R, Binder A, Bouhassira D, Crombez G, et al. DOLORisk: Study protocol for a multi-centre observational study to understand the risk factors and determinants of neuropathic pain [version 2; referees: 2 approved]. Wellcome Open Res. 2019;3:63. 

8.          Scottish Intercollegiate Guideline Network. SIGN 136: Management of chronic pain: A national clinical guideline. Edinburgh; 2013. Available from: https://www.sign.ac.uk/assets/sign136.pdf

9.          National Institute for Health and Care Excellence. Neuropathic pain in adults: pharmacological management in non-specialist settings. London; 2013. Available from: https://www.nice.org.uk/guidance/cg173/resources/neuropathic-pain-in-adults-pharmacological-management-in-nonspecialist-settings-pdf-35109750554053