What is Gabapentin?
Gabapentin is an anticonvulsant widely prescribed for neuropathic pain. It binds to alpha-2-delta calcium channel subunits, reducing excitatory neurotransmitter release involved in pain signaling.
Uses
- Postherpetic neuralgia (FDA-approved)
- Epilepsy — adjunctive therapy for partial seizures
- Diabetic neuropathy (off-label)
- Fibromyalgia (off-label)
- Restless legs syndrome (Horizant form)
Dosage
Postherpetic Neuralgia: Day 1: 300mg once. Day 2: 300mg twice. Day 3+: 300mg three times. May increase to 600mg three times daily (1800mg/day). Max: 3600mg/day.
Side Effects
Common: Dizziness, drowsiness, peripheral edema, fatigue, ataxia
Serious: Suicidal thoughts, DRESS syndrome, respiratory depression with CNS depressants
Precautions
- Adjust dose for renal impairment
- Do not stop abruptly — taper over 1+ week
- FDA warning: increased suicide risk
- Some states classify as Schedule V
How long does Gabapentin take to work for nerve pain?
Some improvement within the first week, but full benefits typically take 2-4 weeks at therapeutic doses.