gabapentin

Adjunctive therapy

Brands: NEURONTIN

Last reviewed 2026-02-12

Reviewed by PsychMed Editorial Team.

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Quick answers

What is gabapentin?
Gabapentin (brand Neurontin) is an anticonvulsant/neuropathic pain agent that is approved for partial seizures (adjunctive therapy) and postherpetic neuralgia. In psychiatry it is sometimes used off label as a sedating, “calming” adjunct—most commonly when clinicians are trying to avoid benzodiazepines, or when comorbid pain, alcohol use disorder, or sleep maintenance complaints are in the picture.
What is NEURONTIN?
NEURONTIN is a brand name for gabapentin.
What is NEURONTIN (gabapentin) used for?
Label indications include: Adjunctive therapy in partial seizures (epilepsy); postherpetic neuralgia (label). Off-label psychiatry use includes anxiety symptoms and insomnia adjuncts.
What drug class is NEURONTIN (gabapentin)?
Alpha-2-delta (α2δ) ligand that modulates voltage-gated calcium channels and reduces excitatory neurotransmitter release.
What strengths does NEURONTIN (gabapentin) come in?
Capsules: 100 mg, 300 mg, 400 mg.

Snapshot

Primary label indications include: Adjunctive therapy in partial seizures (epilepsy); postherpetic neuralgia (label).
Class: Adjunctive therapy
Common US brands: NEURONTIN
Therapeutic drug monitoring not routinely recommended.
Last reviewed: 2026-02-12

Label indications

Adjunctive therapy in partial seizures (epilepsy); postherpetic neuralgia (label). Off-label psychiatry use includes anxiety symptoms and insomnia adjuncts.

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Clinical Highlights

Gabapentin (brand Neurontin) is an anticonvulsant/neuropathic pain agent that is approved for partial seizures (adjunctive therapy) and postherpetic neuralgia. In psychiatry it is sometimes used off label as a sedating, “calming” adjunct—most commonly when clinicians are trying to avoid benzodiazepines, or when comorbid pain, alcohol use disorder, or sleep maintenance complaints are in the picture. Evidence for gabapentin in anxiety disorders is mixed and generally weaker than first-line approaches (CBT, SSRIs/SNRIs). It is best viewed as an adjunct that may reduce hyperarousal and improve sleep continuity, not a primary long-term strategy for generalized anxiety or panic.

The main benefit in real-world psychiatric practice is often “symptom texture”: reduced physiologic tension, fewer nighttime awakenings, and less somatic distress. The main liabilities are sedation, dizziness, and gait instability—risks that are amplified in older adults and in polypharmacy with other CNS depressants.
Gabapentin is cleared renally and is not appreciably metabolized, which limits CYP-based drug interactions but makes renal function the key dosing constraint. When eGFR is reduced, “usual” doses can accumulate and present as confusion, ataxia, and oversedation.
Misuse, diversion, and co-use with opioids or other sedatives are increasingly recognized. Substance use risk screening is common, open-ended refills are typically avoided, and daytime intoxication or escalating dose requests are treated as signals to reassess the plan.
The gabapentin compare view, gabapentin evidence feed, and gabapentin print page can support aligning expectations about sedation, misuse risk, and time-limited use.

Dosing & Formulations

Capsules: 100 mg, 300 mg, 400 mg; tablets: 600 mg, 800 mg; oral solution: 250 mg/5 mL (label). Off-label sleep/anxiety use usually starts low and is titrated slowly to avoid dizziness and next-day impairment. Many clinicians start with a bedtime dose and add daytime doses only if the patient is not sedated and symptoms are clearly daytime-limited.

Short half-life and dose-dependent absorption mean dosing is commonly divided (BID–TID) when used regularly. If a patient is using it only as an intermittent bedtime adjunct, it is often framed as a sleep tool rather than a general “PRN calming” medication.
Renal adjustment is essential. When renal function is impaired, total daily dose is reduced and/or dosing intervals are extended; gait, falls, and cognition are commonly reassessed after each change.
Abrupt discontinuation after sustained daily use can trigger rebound anxiety, insomnia, and withdrawal-like symptoms; tapering is commonly used, especially at higher total daily doses.

Monitoring & Risks

Sedation/ataxia: next-day impairment, falls, and driving safety are commonly monitored, especially during initiation and titration. Cognitive slowing and confusion are more likely when doses are high for the patient’s renal function or when combined with other sedatives.

Peripheral edema and weight gain can occur; reassessment is common when swelling, shortness of breath, or rapid weight changes occur.
Respiratory depression risk increases when gabapentin is combined with opioids, benzodiazepines, alcohol, or in patients with underlying lung disease; sedative “stacking” is generally avoided in higher-risk patients.
Misuse/diversion: watch for early refill requests, lost prescriptions, dose escalation without a clear clinical target, or intoxication.

Drug Interactions

Minimal CYP interactions (not appreciably metabolized), so medication reconciliation focuses on additive CNS depression rather than enzyme inhibition/induction. Antacids containing aluminum/magnesium can reduce gabapentin absorption; dosing is often separated when feasible (label).

Additive sedation with benzodiazepines, opioids, alcohol, and other sedatives; dose reductions and safety planning are common when combinations cannot be avoided.

Practice Notes

Set a concrete target symptom (sleep maintenance, nocturnal anxiety, somatic tension) and reassess within weeks; “PRN forever” patterns that bypass follow-up are generally avoided. If anxiety is persistent and impairing, psychotherapy and SSRI/SNRI strategies are typically prioritized; gabapentin is sometimes used as a bridge or adjunct when sedation is acceptable and misuse risk is low.

Renal function is commonly documented, and dose appropriateness is revisited after medical changes (dehydration, acute illness, new diuretics) that can reduce clearance.
In patients with substance use disorder risk or concurrent opioid therapy, alternative strategies and tighter prescribing controls (limited quantities, no automatic refills) are often considered.

References

Gabapentin prescribing information (Neurontin) — DailyMed (2026)
Gabapentin and Pregabalin for the Treatment of Anxiety Disorders — Clinical Pharmacology in Drug Development (2018)
Treatment of Social Phobia With Gabapentin — Journal of Clinical Psychopharmacology (1999)
Gabapentin misuse, abuse and diversion: a systematic review — Addiction (2016)
Abuse and Misuse of Pregabalin and Gabapentin: A Systematic Review Update — Drugs (2021)