Ezogabine

Actions

• Enhances transmembrane K+ current mediated by KCNQ ion channels.
• Augments GABA-mediated currents.

Metabolism

Hepatic

Enzymes involved

UGT

Elimination

Renal 84%

Enzyme inhibition

Inhibits p-glycoprotein-mediated clearance of digoxin.

Half-life

7-11 hours

Plasma protein binding

80%

Important side-effects

Can cause retinal abnormalities with funduscopic features similar to those seen in retinal pigment dystrophies, which are known to result in damage to the photoreceptors and vision loss.

Urinary retention.

Skin discoloration (bluish, grey-blue or brown). Discoloration of the palate, sclera, and conjunctiva has also been reported.

Confusional state, psychotic symptoms, and hallucinations have been reported.

Suicidal behavior and ideation.

QT interval prolongation.

Spectrum

Adjunctive treatment of focal seizures with or without generalisation

Dosing recommendation

Start with 300 mg/day divided in 3 doses.

Increase in weekly intervals by no more than 50 mg 3 times daily.

Target dose: 600-1200 mg/day divided in 3 doses.

Renal impairment

Dosage adjustment is recommended in patients with creatinine clearance <50 mL/min or patients with end-stage renal disease

Hepatic impairment

No dosage adjustment is recommended in patients with mild hepatic impairment.