Published: 4 March 2021

Publications

Spotlight on gabapentin and pregabalin for neuropathic pain

Published: 4 March 2021
Prescriber Update 42(1): 3
March 2021

The Spotlight series continues with this article on gabapentin and pregabalin, collectively known as gabapentinoids. They are anticonvulsant medicines but also have analgesic and anxiolytic actions.¹ This article focuses on the use of gabapentinoids for neuropathic pain.

Please refer to the medicine data sheets for full prescribing information (search for a data sheet). Note that a careful titration of these medicines is important for patient safety.

Neuropathic pain

Gabapentin and pregabalin are indicated for the treatment of neuropathic pain. Use of gabapentinoids for other types of pain (eg, chronic or musculoskeletal pain) is unapproved and is not supported by clinical evidence.

Neuropathic pain is typically described as shooting, stabbing, burning, tingling, like an electric shock, tightness, numbness, and prickling.² Patients may also describe allodynia (pain due to a stimulus that does not normally provoke pain, such as soft touch) or hyperalgesia (an exaggerated or increased response to a stimulus that is normally painful).²

Guidelines for pharmacological treatment of neuropathic pain generally recommend a step-wise approach, starting with a tricyclic antidepressant, serotonin-noradrenaline reuptake inhibitor, or a gabapentinoid.^2–4

Adverse events

Dizziness and somnolence

Advise patients not to drive or operate complex machinery until it is known whether these medicines affect their ability to perform these activities.^5,6 In clinical trials for treatment of neuropathic pain, dizziness and somnolence were the most commonly reported adverse events for pregabalin and gabapentin compared to placebo.^5,6 Dizziness and somnolence were also the most commonly reported reasons for treatment discontinuation for both medicines.^5,6

Abuse and dependence

Internationally, cases of abuse and dependence have been reported with gabapentinoids.^5,6 Evaluate patients for a history of substance abuse and observe for signs of misuse or abuse (eg, development of tolerance, increasing doses, drug-seeking behaviour).^5,6

Concurrent treatment with opioids and gabapentinoids increases the risk of abuse and dependence.^7–9

Concurrent use of gabapentinoids with CNS depressants

Concurrent treatment with CNS depressants (eg, opioids) and gabapentin or pregabalin should be avoided.^5,6 In the event that these medicines have to be used together, the patient must be closely observed for signs of CNS depression, such as somnolence, sedation and respiratory depression, and the doses adjusted as needed.⁵

Suicidal behaviour and ideation

Antiepileptics, including gabapentin and pregabalin, can increase the risk of suicidal thoughts or behaviour when used for any indication.^5,6 Monitor patients for emergence or worsening of depression, suicidal thoughts or behaviour, and/or any unusual changes in mood or behaviour.^5,6

New Zealand adverse reaction reports

Up to 30 June 2020, the Centre for Adverse Reactions Monitoring (CARM) had received 50 adverse reaction reports for pregabalin and 248 reports for gabapentin (for any indication).

Of the 50 reports where pregabalin was coded as the suspect medicine, withdrawal syndrome was reported in 7 cases (CARM IDs: 094871, 096116, 096253, 119601, 131036, 133627, 135012).

Of the 248 reports where gabapentin was the coded as the suspect medicine, withdrawal syndrome was reported in 7 cases (CARM IDs: 036058, 051356, 062548, 064084, 093296, 135012, 135138).

References

1. Mathieson S, Lin C-W C, Underwood M, et al. 2020. Pregabalin and gabapentin for pain. BMJ 369: m1315. DOI: 10.1136/bmj.m1315 (accessed 15 February 2021).
2. National Institute for Health Care Excellence (NICE). 2013. Neuropathic pain in adults: Pharmacological management in non-specialist settings URL: www.nice.org.uk/guidance/cg173 (accessed 7 December 2020).
3. BPAC^NZ. 2018. Prescribing gabapentin and pregabalin: Upcoming subsidy changes. URL: bpac.org.nz/2018/gabapentinoids.aspx (accessed 15 February 2021).
4. Bates D, Schultheis BC, Hanes MC, et al. 2019. A comprehensive algorithm for management of neuropathic pain. Pain Medicine 20(Suppl 1): S2–S12. DOI:10.1093/pm/pnz075 (accessed 4 February 2021).
5. Pfizer New Zealand Ltd. 2020. Neurontin New Zealand Data Sheet May 2020. URL: medsafe.govt.nz/profs/Datasheet/n/Neurontincaptab.pdf (accessed 7 December 2020).
6. Pfizer New Zealand Ltd. 2020. Pregabalin Pfizer New Zealand Data Sheet January 2020. URL: medsafe.govt.nz/profs/datasheet/l/Lyricacaps.pdf (accessed 7 December 2020).
7. Peckham A, Ananickal M and Sclar D. 2018. Gabapentin use, abuse, and the US opioid epidemic: the case for reclassification as a controlled substance and the need for pharmacovigilance. Risk Management and Healthcare Policy 11: 109–16. DOI: 10.2147/rmhp.s168504 (accessed 7 December 2020).
8. Baird C, Fox P and Colvin L. 2014. Gabapentinoid abuse in order to potentiate the effect of methadone: a survey among substance misusers. European Addiction Research 20(3): 115–8. DOI: 10.1159/000355268 (accessed 7 December 2020).
9. Reeves R and Ladner M. 2014. Potentiation of the effect of buprenorphine/naloxone with gabapentin or quetiapine. American Journal of Psychiatry 171(6): 691. DOI: 10.1176/appi.ajp.2014.13111526 (accessed 7 December 2020).