From the Guidelines

Gabapentin is effective for treating sciatica, but with small to moderate benefits.

The evidence suggests that gabapentin is associated with small, short-term benefits in patients with radiculopathy 1.
Gabapentin has not been directly compared with other medications or treatments for sciatica, and there is insufficient evidence to recommend for or against other antiepileptic drugs for back pain with or without radiculopathy.
The use of gabapentin for sciatica is not FDA-approved, but it may be considered for patients who do not improve with self-care options.
Systemic corticosteroids are not recommended for treatment of low back pain with or without sciatica, as they have not been shown to be more effective than placebo 1.
Nonpharmacologic therapy, such as spinal manipulation, exercise therapy, and acupuncture, may be considered for patients with sciatica who do not improve with self-care options 1.

The evidence for the effectiveness of gabapentin for sciatica is based on small, short-term trials, and more research is needed to fully understand its benefits and risks.
Gabapentin should be used with caution, as it can have adverse effects, such as dizziness, drowsiness, and nausea.
Patients with sciatica should be assessed and treated for underlying conditions, such as depression, which is common in patients with chronic low back pain 1.

From the Research

Gabapentin has been shown to be effective in treating sciatica in some studies, with significant reductions in pain intensity and disability 2, 3, 4.
A study published in 2008 reported two cases of patients with sciatica who were successfully treated with gabapentin, with significant improvements in pain and disability 2.
A 2016 study found that gabapentin superadded to a pre-existent regime containing amitriptyline was effective in reducing pain and disability in patients with chronic sciatica, although side effects were common 3.
A 2019 randomized clinical trial found that gabapentin was superior to pregabalin in reducing pain intensity and disability in adults with chronic sciatica, with fewer and less severe adverse events 4.

A 2016 review found that gabapentin and pregabalin had comparable efficacy and side effect profiles for treating neuropathic pain, including sciatica, although the evidence was limited and indirect 5.
A 2017 systematic review found that gabapentin was effective in reducing pain intensity in adults with chronic neuropathic pain, including sciatica, although the evidence was moderate-quality and limited to specific conditions 6.

Gabapentin has been associated with common side effects such as dizziness, somnolence, and peripheral edema, although these are often mild and transient 3, 6, 4.
A 2019 study found that gabapentin had fewer and less severe adverse events compared to pregabalin in patients with chronic sciatica 4.