The latest and greatest new med seems to be Potiga (Ezogabine) which is certainly promising news for the epilepsy community. Developed for adults (18 or over) as an add-on drug for partial seizures, it’s a revolutionary new anti-seizure medication which prevents seizures in a way completely different from currently existing AEDs.
The way it appears to work is by enhancing the potassium currents mediated by a particular family of ion channels known as KCNQ. By activating these specific channels on nerve cells, Potiga is thought to stabilize these nerve cells and reduce brain excitability.
It may also have an impact on another neurotransmitter, known as GABA, which is known to cause the nerve cells to calm in some manner. There are several other seizure drugs that work via increasing GABA in the cell; however Potiga will be the first drug to prevent seizures by the potassium channel mechanism.
In three clinical studies, Potiga reduced seizure frequency by 27% for 600 mg doses…25% at 900 mg…and up to 24% seizure reduction for 1200 mg per day. Supplied in 50, 200, 300, and 400 mg size pills, the medication is meant to be taken three times a day, starting at a low dose and titrating up if necessary.
The initial dosage should be 100 mg, three times daily (300 mg per day). The dose can then be increased at weekly intervals by no more than 50 mg, three times daily (increasing the daily dose to no more than 150 mg per day) up to a maintenance level of 200 mg to 400 mg three times daily (600 mg to 1,200 mg per day), based on individual patient response and tolerability.
But lower doses may be recommended for people with liver or kidney disease. Similarly, lower dosages are recommended for people over the age of 65. For older individuals, the usual starting dose is 50 mg, taken three times daily and the maximum amount is 250 mg taken three times daily.
Potiga can interact with Carbamazepine, Dilantin (phenytoin), and Lamictal (lamotrigine), decreasing the amount of Potiga in your system by 31% to 34%. So, an increase in the dose should be considered when adding Potiga to those drugs.
It can also cause a “relaxed bladder” which results in urinary retention, or difficulty in emptying the bladder fully. When that occurs, it’s generally within the first six months of treatment, although it can also occur later. Because of the risk of urinary retention, urologic symptoms, such as the inability to start to urinate, weak urine stream, or pain with urination, should be carefully monitored. Urinary retention is a unique side-effect among medications used to treat seizures.
In clinical trials, the most common adverse reactions reported by patients taking Potiga included: dizziness, fatigue, confusion, vertigo, tremors, abnormal coordination, balance problems, blurred vision, memory impairment, and confusion.
Most of the adverse reactions appear to be dose related, especially neuro-psychiatric symptoms, such as anxiety, depression, confusion, hallucinations, psychotic symptoms and suicide thoughts. But, when Potiga is discontinued, these symptoms usually resolve within seven days.
There are also studies underway to see if Potiga might also be a potential treatment for migraine, neuropathic pain and some other neurological conditions.
Of course, since it’s such a new drug, the jury is still out on long-term ramifications. But hopes are high in the scientific and medical community that this indeed may prove to be a new and effective add-on treatment for partial seizures.