Does gabapentin work for nerve pain?
Gabapentin reduces neuropathic pain in conditions like postherpetic neuralgia and diabetic peripheral neuropathy. A Cochrane review of 37 trials with over 6,000 patients found it lowers pain intensity by at least 50% in about 30% of people, compared to 15% on placebo, with number needed to treat around 6-7 for moderate benefit.[1] It acts by binding to voltage-gated calcium channels, dampening nerve hyperexcitability.[2]
How effective is it compared to placebo?
Placebo-controlled trials show gabapentin cuts average pain scores by 1.5-2 points on a 10-point scale. Benefits peak at doses of 1,800-3,600 mg/day, split into three doses. Response rates are higher in central neuropathic pain (e.g., spinal cord injury) than peripheral types.[1][3] Evidence is weaker for chemotherapy-induced neuropathy or HIV-related pain due to smaller studies.
What do guidelines recommend for nerve pain?
American Academy of Neurology guidelines endorse gabapentin as first-line for postherpetic neuralgia (Level A evidence) and diabetic neuropathy (Level B). NICE in the UK lists it as an initial option alongside duloxetine or amitriptyline. It's less favored now for fibromyalgia due to mixed data.[4][5] Guidelines stress titrating slowly to minimize side effects.
How does gabapentin stack up against other treatments?
Versus tricyclic antidepressants like amitriptyline, gabapentin matches efficacy but causes less sedation and dry mouth, though more dizziness.[1] Pregabalin (Lyrica), a gabapentin analog, shows similar results but faster onset and once/twice-daily dosing.[6] Topical options like lidocaine patches work for localized pain without systemic effects. Opioids are avoided long-term due to risks.
What are common side effects and who should avoid it?
Dizziness (20-30%), somnolence (15-25%), and ataxia affect most users, leading to 20% dropout rates in trials. Risks rise with renal impairment—dose adjustments needed as it's cleared by kidneys. Rare serious issues include suicidal thoughts and respiratory depression, especially with opioids.[3][7] Not advised in pregnancy (Category C) or for kids under 3.
Why the off-label use and generic status?
Originally for epilepsy, gabapentin's patent expired in 2004, making it cheap (under $20/month generic). Heavy marketing pushed off-label neuropathic pain use, now standard despite modest effect sizes. Some patients report no benefit after months, prompting switches.[8]
[1]: Wiffen PJ et al. Gabapentin for chronic neuropathic pain in adults. Cochrane Database Syst Rev. 2017. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD007938.pub4/full
[2]: Patel R et al. Mechanisms of the gabapentinoids... Pain. 2018. https://pubmed.ncbi.nlm.nih.gov/30113483/
[3]: Moore A et al. Gabapentin for acute postherpetic neuralgia. Cochrane Database Syst Rev. 2014.
[4]: Bril V et al. Evidence-based guideline: Treatment of painful diabetic neuropathy. Neurology. 2011.
[5]: NICE. Neuropathic pain in adults. 2020. https://www.nice.org.uk/guidance/cg173
[6]: Dworkin RH et al. Pregabalin vs placebo/others in neuropathic pain. Pain. 2007.
[7]: FDA Gabapentin label. https://www.accessdata.fda.gov/drugsatfdadocs/label/2017/020235s064020882s047_021129s046lbl.pdf
[8]: Goodman & Gilman. The Pharmacological Basis of Therapeutics. 13th ed. Gabapentin section.