Ezogabine Dosage

Applies to the following strengths: 50 mg; 200 mg; 300 mg; 400 mg

Usual Adult Dose for Seizures

Initial dose: 100 mg orally 3 times a day for 1 week.
Titration: Gradual dosage increase of no more than 50 mg orally 3 times a day, at weekly intervals.
Maintenance dose: 200 mg to 400 mg orally 3 times a day, based on individual patient response and tolerability.
Maximum dose: 400 mg orally 3 times a day.

Comments:

If this drug is discontinued, the dosage should be gradually reduced over a period of at least 3 weeks, unless safety concerns require abrupt withdrawal.

Use: Adjunctive treatment of partial-onset seizures in patients aged 18 years and older who have responded inadequately to several alternative treatments and for whom the benefits outweigh the risk of retinal abnormalities and potential decline in visual acuity.

Usual Geriatric Dose for Seizures

Patients aged 65 years and older:

Initial dose: 50 mg orally 3 times a day for 1 week.
Titration: Gradual dosage increase of no more than 50 mg orally 3 times a day, at weekly intervals.
Maximum dose: 250 mg orally 3 times a day.

Comments:

If this drug is discontinued, the dosage should be gradually reduced over a period of at least 3 weeks, unless safety concerns require abrupt withdrawal.

Renal Dose Adjustments

Mild Renal Impairment: No adjustment recommended.

CrCl less than 50 mL/min or End-Stage Renal Disease on Dialysis:

Initial dose: 50 mg orally 3 times a day for 1 week.
Titration: Gradual dosage increase of no more than 50 mg orally 3 times a day, at weekly intervals.
Maximum dose: 200 mg orally 3 times a day.

Liver Dose Adjustments

Mild Liver Impairment: No adjustment recommended.

Moderate to Severe Liver Impairment (Child-Pugh 7 to 9):

Initial dose: 50 mg orally 3 times a day for 1 week.
Titration: Gradual dosage increase of no more than 50 mg orally 3 times a day, at weekly intervals.
Maximum dose: 250 mg orally 3 times a day.

Severe Liver Impairment (Child-Pugh greater than 9):

Initial dose: 50 mg orally 3 times a day for 1 week.
Titration: Gradual dosage increase of no more than 50 mg orally 3 times a day, at weekly intervals.
Maximum dose: 200 mg orally 3 times a day.

Precautions

US BOXED WARNING:
RETINAL ABNORMALITIES AND POTENTIAL VISION LOSS:

This drug 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.
In addition, macular abnormalities characterized as vitelliform lesions have been observed; these lesions have been identified most consistently with optical coherence tomography imaging.
Some patients with retinal abnormalities have been found to have abnormal visual acuity. It is not possible to determine whether this drug caused this decreased visual acuity.
The rate of progression of retinal abnormalities and their reversibility are unknown; however, reversibility of retinal pigmentary abnormalities and partial resolution of vitelliform lesions have been reported after discontinuation of this drug in some patients.
All patients should have systematic visual monitoring performed at baseline and every 6 months. Testing should include visual acuity, dilated fundus photography, and optical coherence tomography. Fluorescein angiograms, perimetry, and electroretinograms are additional tests to consider.
This drug should only be used in patients who have responded inadequately to several alternative treatments and for whom the benefits outweigh the potential risk of vision loss.
Treatment should be discontinued in patients who fail to show substantial clinical benefit after adequate titration, or if retinal pigmentary abnormalities or vision changes are detected (unless no other suitable treatment options are available and the benefits outweigh the risks).

Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.

US Controlled Substance: Schedule V

Dialysis

End-Stage Renal Disease on Dialysis:

Initial dose: 50 mg orally 3 times a day for 1 week.
Titration: Gradual dosage increase of no more than 50 mg orally 3 times a day, at weekly intervals.
Maximum dose: 200 mg orally 3 times a day.

Other Comments

Administration Advice:

Take this drug with or without food.
Swallow tablets whole; do not chew, crush, or divide drug tablets.

General:

Clinical trials showed limited evidence of additional improvement in seizure reduction but an increase in adverse events and discontinuations with dosage of 1,200 mg per day compared with 900 mg per day.
Unless no other suitable treatment options are available and the benefits outweigh the potential risk of vision loss, treatment should be discontinued in patients who fail to show substantial clinical benefit after adequate titration or if retinal pigmentary abnormalities or vision changes are detected.
Patients who cannot be monitored should usually not be treated with this drug.

Monitoring:

Cardiovascular: QT interval
Dermatologic: Skin discoloration
Genitourinary: Urologic symptoms
Nervous System: Dizziness and somnolence
Ocular: Visual function testing (baseline and every 6 months)
Psychiatric: Confusional state, psychotic symptoms, hallucinations, depression, suicidal thoughts/behaviors, unusual changes in mood/behavior

Patient Advice:

This drug may cause dizziness, drowsiness, and vision problems; avoid driving and other activities such as operating machinery until you know how this drug affects you.