Introduction
Gabapentin (Neurontin) was originally developed as an anticonvulsant but is now widely used for neuropathic pain, fibromyalgia, alcohol withdrawal, and off-label anxiety treatment.
FDA-Approved Uses
Postherpetic neuralgia (shingles pain) and epilepsy are the two FDA-approved indications. All other uses are off-label but evidence-supported.
How Gabapentin Works
It binds to the alpha-2-delta subunit of voltage-gated calcium channels in the CNS, reducing the release of excitatory neurotransmitters involved in pain and seizure activity.
Dosing
Doses range widely from 100 mg to 3,600 mg daily in divided doses. Titrate slowly to minimize dizziness and sedation, which are common at initiation.
Common Side Effects
Dizziness, somnolence, peripheral edema, and ataxia are most common. Cognitive effects ("gabapentin fog") can affect concentration and memory.
Abuse Potential
While not federally scheduled, gabapentin has recognized abuse potential, especially in opioid-dependent patients. Many states now require controlled substance monitoring.
Renal Dosing
Gabapentin is renally eliminated. Dose reduction is required in patients with CrCl < 60 mL/min to avoid toxicity.
Tapering
Do not stop gabapentin abruptly — gradual tapering over weeks reduces the risk of withdrawal seizures and rebound pain.
Conclusion
Gabapentin is a versatile medication for nerve pain and related conditions. Responsible prescribing and monitoring remain essential given its expanding off-label use.