Is gabapentin (Neurontin) indicated for neuropathic pain?

From the Guidelines

Gabapentin is indicated for neuropathic pain, particularly for diabetic peripheral neuropathy, postherpetic neuralgia, and other forms of neuropathic pain, as it has shown efficacy in reducing pain intensity and improving quality of life 1.

Key Considerations

• The medication should be started at a low dose, such as 100-300 mg nightly, and gradually increased to 900-3600 mg daily in divided doses, with dose increments of 50%-100% every few days, as tolerated by the patient 1.
• Gabapentin should be taken with food to improve absorption and reduce gastrointestinal side effects.
• Patients should expect that it may take 2-4 weeks to experience the full therapeutic effect.
• Common side effects include dizziness, somnolence, peripheral edema, and gait disturbances, which are typically more pronounced when initiating therapy or increasing doses.

Mechanism of Action

• Gabapentin works by binding to the alpha-2-delta subunit of voltage-gated calcium channels in the central nervous system, which reduces the release of excitatory neurotransmitters involved in pain signaling.

Special Considerations

• The medication should be tapered gradually when discontinuing to avoid withdrawal symptoms.
• Gabapentin requires dosage reduction in patients with renal insufficiency, and dosage adjustments can be made in relation to creatinine clearance 1.
• Gabapentin can produce dose-dependent dizziness and sedation, which can be reduced by starting with lower dosages and titrating cautiously 1.

From the Research

Indications for Gabapentin in Neuropathic Pain

Gabapentin is indicated for the treatment of neuropathic pain, specifically:

• Postherpetic neuralgia (PHN) 2, 3, 4, 5, 6
• Painful diabetic neuropathy (PDN) 2, 3, 4, 5, 6
• Other neuropathic pain conditions, although evidence is limited 2, 3

Efficacy of Gabapentin in Neuropathic Pain

The efficacy of gabapentin in neuropathic pain is supported by several studies, including:

• A 2017 Cochrane review that found gabapentin to be effective in reducing pain in patients with PHN and PDN 2
• A 2014 Cochrane review that found gabapentin to be effective in reducing pain in patients with PHN and PDN, although the evidence was considered to be of moderate quality 3
• A 2002 study that found gabapentin to be effective in relieving allodynia and hyperalgesia in animal models of neuropathic pain 4
• A 2000 study that found gabapentin to be effective in reducing pain in patients with PHN and PDN 5
• A 2018 study that found oral gabapentin to be associated with pain reduction of at least 50% in 14% to 17% more patients with PHN or PDN than placebo 6

Adverse Effects of Gabapentin

Gabapentin is associated with several adverse effects, including:

• Dizziness 2, 3, 4, 5
• Somnolence 2, 3, 4, 5
• Peripheral oedema 2, 3
• Gait disturbance 2, 3
• Serious adverse events, although these are rare 2, 3