Abstracts

Rationale: Perampanel (PER) was created in Japan and approved to prescribe for the treatment of epilepsy in 2016. However, its use has been limited in combination therapy with the other anti-epileptic drugs. At the beginning on the market, PER was mainly used lately for patients with medically refractory epilepsy, such as the fourth or fifth medication. Then our primary report with early experience of PER revealed that seizure freedom was only 19.3%. Now PER is more used earlier in the treatment process. Then effectiveness of PER in seizure control was researched again. Methods: Seventy patients treated with PER were retrospectively reviewed. These patients were evaluated and treated at the Comprehensive Epilepsy Center of the Seirei Hamamatsu General Hospital, the Department of Neurosurgery of the Seirei Numazu Hospital, and the Department of Neurosurgery of the Municipal Kosai Hospital. The mean follow-up period was 477.9 days. Seizure reduction by PER, the numbers of concomitant anti-epileptic drugs, doses of PER, and adverse reactions by PER were reviewed. Frequency of seizures was reported by patients with daily seizure notes or memos. Results: Thirty-seven female and 33 male patients were included in the analysis. The ages of starting PER varied from 11 through 76. The mean age was 37.9 years old. Seventy percent of them were symptomatic localization-related epilepsy, 21.4% were symptomatic generalized epilepsy, and 8.6% were idiopathic generalized epilepsy. Most of the patients had frequent seizures, because 31.4% had daily seizures and 38.6% had weekly seizures. The mean numbers of concomitant anti-epileptic drugs were 2.8 drugs. The outcome of seizure reduction demonstrated that 44.3% of patients obtained seizure freedom by PER and 22.9% had a more than 50% seizure reduction. Therefore the responder rate with a more than 50% seizure reduction was 67.1%. Early add-on treatment with PER (N=26), that is, one anti-epileptic drug plus PER or two anti-epileptic drugs plus PER, was obviously effective since the rate of seizure freedom was significantly higher (61.5%) as compared to that of late add-on (34.9%). The dose of PER at this research varied from 1mg/day through 12mg/day, and the mean dose of PER was 4.7mg/day. Three major adverse reactions were the same as our previous report and were somnolence, irritability, and dizziness. Twenty-nine patients complained of some adverse reactions. However, 12 patients among them tolerated and kept PER for their treatment. Conclusions: PER was effective in the treatment of epilepsy and provided patients with more seizure freedom by early add-on. PER has been already approved for monotherapy in USA, and a trial of monotherapy has been running in Japan. Although more researches are still necessary to recognize PER as one the first line medications for epilepsy, monotherapy with PER possibly has potential to be used practically. Funding: No funding was received.