Gabapentin
NEURONTIN
Pronunciation: gab-a-PEN-tin (nyoo-RON-tin)
“Gabba pen tin = Neuron tin”
Pens shaped like neurons with heads of Yo Gabba Gabba characters
What it isAlpha-2-delta calcium-channel subunit ligand for seizures and postherpetic neuralgia; also used off label for other neuralgia.
Why it mattersFirst-line neuropathic-pain option alongside TCAs, SNRIs and pregabalin; inexpensive generic without hepatic metabolism or CYP interactions.
What it changesReduce in renal impairment; accumulation sedates. Opioids add respiratory depression, and misuse is increasingly recognized.
Pearls
- Saturable absorption: higher doses yield diminishing exposure, unlike pregabalin.
- Off-label for anxiety and hot flashes; pregabalin better studied in GAD.
- Edema, weight gain, ataxia; behavioral changes in children.
Gabapentin prescription history
Animated chart of estimated U.S. prescriptions per year, Antiseizure meds (1869–2026). Gabapentin enters in 1994 (estimated).
FDA-approved for
- seizures (1993)
- postherpetic neuralgia (2002)
- restless legs (enacarbil) (2011)
Off-label
- anxiety
- neuropathic pain
- alcohol use disorder
- hot flashes
- restless legs
Principal riskSedation and dizziness, additive with opioids
Classes and tags
Clinical profile
Legacy pregnancy categoryC
Defining liabilitySedation, dizziness and misuse potential; respiratory depression increases with opioids.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Postherpetic neuralgia | Adults | 300 mg QD (day 1) → 300 mg BID (day 2) → 300 mg TID (day 3) | 600 mg TID (1800 mg/day) | 1800 mg/day |
| Partial onset seizures | ≥12 yr | 300 mg TID | 300–600 mg TID | 3600 mg/day |
| Partial onset seizures | Peds 3–11 yr | 10–15 mg/kg/day TID | 3–4 yr: 40 mg/kg/day; 5–11 yr: 25–35 mg/kg/day |
Renal Adjust by creatinine clearance in patients ≥12 yr; reduce dose for renal impairment and supplement after hemodialysis
Hepatic Undefined
Max interval between doses ≤12 h
Instructions
- Do not discontinue abruptly — taper over ≥1 week to reduce seizure/withdrawal risk
- Maximum time between doses should not exceed 12 h
Available strengths
- cap 100, 200, 300, 400 mg
- tab 100, 300, 400, 450, 600, 750, 800, 900 mg
- sol 250 mg/5 mL
Cautions
- DRESS/multiorgan hypersensitivity
- Anaphylaxis and angioedema
- Somnolence/sedation, dizziness, driving impairment
- Suicidal behavior and ideation
- Increased seizure risk with abrupt discontinuation
- Respiratory depression with CNS depressants/opioids or respiratory impairment
- Neuropsychiatric reactions in children 3–12 yr
Adverse reactions
- Dizziness
- Somnolence
- Peripheral edema
- Ataxia
- Fatigue
- Nystagmus
- (peds) viral infection, fever, nausea/vomiting, hostility
Pregnancy Available data do not indicate increased risk of major birth defects/miscarriage; developmental toxicity in animals; neonatal withdrawal reported with concomitant opioids near delivery
Lactation Secreted in human milk; effects on infant unknown
Cost
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 100 mg | cap | 30 qd | $0.66 | not offered |
| 200 mg | cap | 30 qd | not offered | |
| 300 mg | cap | 30 qd | $0.94 | not offered |
| 400 mg | cap | 30 qd | $1.27 | not offered |
Other forms: Gabapentin ER (GRALISE)
Generic entry2003
Open Gabapentin in the interactive console ↗
Memory aids: interaction avatars
Open Gabapentin in the interactive console ↗
Self-check
- Why do gabapentin dose increases yield diminishing exposure gains?
Saturable absorption. - What respiratory risk is added by opioids with gabapentin?
Respiratory depression.