Gabapentin

Actions

• Blocks voltage-gated Ca++ channels.
• Enhances H current.
• Suppresses presynaptic vesicle release.
• Suppresses NMDA receptor.

Metabolism

Not significantly metabolized.

Elimination

Renal

Therapeutic serum concentration range

4-16 μg/ml

Half-life

5-9 hours

Plasma protein binding

0%

Important side-effects

Suicidal behavior and ideation

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)

Indications

Focal seizures with or without generalization.

May aggravate myoclonic seizures.

Dosing recommendation

Start with 300–900 mg/day.

Increase to target dose over 5–10 days.

Target dose: 900–3600 mg/day divided in 2-3 doses.

Renal impairment

Dose reduction is necessary in patients with impaired renal function.

Hepatic impairment

No adjustment is necessary in patients with impaired hepatic function.