Antiepileptic - harkoseride

An abnormal increase in the electrical activity of the central nervous system is likely to result in an epileptic fit. These involve disruptions to sensory or motor functions, altering consciousness and the sufferers can all too easily injure themselves.

Prevention is the key to managing epilepsy, and to a great extent it is controlled by drugs. However, refractory epilepsy remains a problem, although the second generation anticonvulsants have greatly improved the situation. But problems with efficacy and side effects remain, and new, improved anticonvulsants are much needed.

A new generation of antiepileptic medicines is being developed. One such product is harkoseride, also referred to as erlosamide, which is being investigated by Schwarz Pharma, under licence from Harris FRC.

A total of 100 patients who had more than four refractory partial seizures every month were given harkoseride in a multicentre open label clinical trial.¹

After a four week baseline period, subjects first underwent an eight week titration period in which the initial daily dose of 100mg was slowly increased to a maximum of 600mg, or until the maximum tolerated dose was reached. A four-week maintenance period followed. The drug reduced the frequency of seizures, and at the end of the maintenance period, 56% of patients had frequency reductions of at least 25%, and 33% had at least 50% fewer seizures. The median mean tolerated dose was 300mg/day, and no serious adverse events were reported.

In a further open label trial, its tolerability and efficacy in reducing the frequency of partial seizures was investigated.² Using the same dosing regimen as the previous trial in 90 patients with refractory partial seizures, harkoseride reduced median seizure frequency by 31.8%.

The drug is also being investigated as a potential treatment for neuropathic pain, for which as yet there are no approved drugs in common use.