What to Know About Potiga (Ezogabine)

Potiga (ezogabine, retigabine) is an anti-epileptic drug (AED) that was approved for seizure prevention by the U.S. Food and Drug Administration (FDA). The manufacturer discontinued this medication in 2017.

Potiga was available in tablet form and was approved for adults ages 18 and over. It was reported to cause a number of side effects, including changes in the retina (an important region of the eye). There were several safety warnings issued by the FDA prior to its withdrawal from the market.

Uses

Potiga is approved as an adjunctive treatment for the prevention of partial seizures in epilepsy.

Partial seizures are characterized by involuntary (not on purpose) repetitive jerking or shaking movements of the body that can also affect your level of consciousness. Partial seizures are caused by erratic nerve activity in one region of the brain.

Adjunctive AED therapy is a medication that is recommended for use along with another AED. It is not expected to prevent seizures when taken as monotherapy (on its own).

Potiga was used for seizure prevention. It was not recommended for the treatment of an ongoing seizure episode because it has not been shown to stop an active seizure.

Potiga is believed to work by interacting with potassium channels and gamma-aminobutyric acid (GABA).

• Potassium channels are proteins on the surface of a nerve. They facilitate nerve function. Potiga slows down the action of potassium channels. This prevents seizures by inhibiting over-activity of the nerves in the brain
• GABA is a neurotransmitter that decreases nerve action, and Potiga may increase the action of GABA, preventing the excessive nerve action of seizures.

Off-Label Uses 

There were not widely known off-label uses for Potiga.

Ezogabine has been studied in research trials in the context of depression and bipolar disorder.

Before Taking

Taking Potiga can worsen several medical conditions. This medication is considered potentially unsafe during pregnancy and therefore is not typically recommended during pregnancy.

Precautions and Contraindications 

If you have the following conditions, precautions are recommended when taking Potiga:

• Urinary retention (trouble urinating): If you have urinary retention, the manufacturer recommends that you have your bladder function monitored when taking Potiga.
• Neuropsychiatric symptoms: If you have trouble thinking or episodes of confusion or psychosis, Potiga may worsen these symptoms.
• Dizziness and somnolence (excessive sleepiness): If you already experience dizziness or somnolence prior to using Potiga, your medical team may monitor these symptoms to see if they worsen while you are taking this medication.
• QT prolongation: Potiga can worsen QT prolongation, a heart condition. If you have heart problems or if you take medications that can cause heart problems, you should have routine electrocardiogram (EKG) so your doctor can monitor your QT interval while taking Potiga.
• Suicidal behavior and ideation (thinking about suicide): Anyone who has a history of suicidal thoughts or actions should be regularly monitored for these symptoms when taking Potiga.

Dosage

Potiga was available in tablets that came in strengths of 50 milligrams (mg), 200 mg, 300 mg, and 400 mg.

The recommended dose ranges between 600 mg per day and 1200 mg per day. Generally, the target dose is the dose at which seizures are well controlled without unmanageable side effects.

The medication should be started at a dose of 300 mg per day (100 mg three times per day) for the first week. The dose should be gradually increased by a maximum of 150 mg per day until the target dose is reached.

Modifications

The manufacturer of Potiga recommends that people who are elderly or who have kidney or liver problems take a lower than the standard dose of the medication. Your doctor would adjust your target dose based on seizure control and side effects.

How to Take and Store

This medication must be taken three times per day in equally divided doses. As with many AEDs, the dose needs to be spaced evenly throughout the day to maintain a stable blood level.

Skipping or missing doses can result in a seizure. It is important to discuss a plan with your doctor regarding missed AED medications. Your doctor will give you specific instructions regarding whether you should take your missed dose to catch up or whether you should skip it and resume your medication at your regularly scheduled time. This depends on your type and frequency of seizures.

Potiga can be taken with or without food.

The tablets have to be stored at a temperature of 25 degrees Celcius (77 degrees Fahrenheit). If you need to take it with you for short trips, you can keep the medication at a temperature of 15 degrees to 30 degrees Celcius (59 degrees to 86 degrees Fahrenheit).

Side Effects

This medication, like most AEDs can cause a number of side effects. Taking AED medication is based on weighing the benefits and risks.

Not everyone experiences the same side effects. You may not experience side effects, or they can be intolerable. It is not possible to predict how you will react to medication until you start taking it.

Common

According to the manufacturer of Potiga, the most common side effects are:

• Dizziness
• Somnolence (extreme sleepiness)
• Fatigue
• Confusion
• Vertigo (a sense that the room is spinning)
• Tremors
• Coordination and balance problems
• Diplopia (double vision)
• Attention problems
• Impaired memory
• Asthenia (weakness and lack of energy)
• Blurred vision
• Trouble waking
• Aphasia (language problems)
• Dysarthria (slurred speech)

Severe

Retinal abnormalities caused by this medication were of particular concern and may be associated with vision loss.

It is recommended that anyone who is taking Potiga or other forms of this medication have ophthalmologic evaluations every six months to identify any changes in the eye. The changes associated with Potiga include retinal pigment changes and macular changes.

Skin discoloration has been described as bluish or brownish and was most common on the fingers and toes.

Warnings and Interactions

Potiga, like all AEDs, should not be stopped abruptly. Sudden discontinuation can trigger a seizure. It is important to follow your doctor’s recommendations for gradually reducing the dose before completely stopping the medication.

Interactions

Phenytoin and carbamazepine are anti-seizure medications that can reduce the levels of Potiga.

This medication can interfere with the level of digoxin (a heart medication), and the manufacturer recommends that anyone who takes Potiga and digoxin should have digoxin levels monitored.