Authors :
Presenting Author: Fumihiko Kawai, MD – Saitama Medical University
Satsuki Watanabe, M.D., PhD. – Associate Professor, Department of Psychiaty, Faculty of Medicine, Saitama Medical University; Ryosuke Mizumura, Phermacist – Department of Psychiaty, Faculty of Medicine – Saitama Medical University; Yoshiko Murata, M.D., PhD. – Department of Psychiaty, Faculty of Medicine – Saitama Medical University; Koji Matsuo, M.D., PhD. – Professor, Department of Psychiaty, Faculty of Medicine, Saitama Medical University
Rationale:
Psychiatric symptoms are often a problematic side effect of anti-seizure medication. Perampanel (PER) is one of the anti-seizure medications with a relatively high incidence of irritability. Some studies have reported that the incidence of psychiatric symptoms was lower when ASDs were started at lower doses. We hypothesized that a similar result could be obtained with PER. In the present study, we compared the incidence of irritability between starting doses of 1 mg and 2 mg of PER.
Methods:
We conducted a retrospective study using medical records and included patients whose PER was started at the Department of Neuropsychiatry of Saitama Medical University between July 2017 and August 2023. Patients were divided into 1 mg and 2 mg starting groups for comparison. Patients who reported "irritability" or "anger" in their medical records during the observation period were defined as those who developed irritability. Fisher's direct probability test was used for statistical analysis. Statistical significance was accepted at an alpha level of 0.05. This study was conducted with the approval of the Saitama Medical University Hospital IRB.
Results:
Seventy-seven patients were included in the study. There were 46 patients in the 1 mg group (mean age 48.3, 26 male) and 31 in the 2 mg group (mean age 41.0, 13 male). Incidence of side effects were 42.6 % in the 1mg group and 54.8 % in the 2 mg group, and there was no significant difference between the groups (p=0.360). Incidence of irritability was 12.2 % in the 1mg group and 34.8 % in the 2 mg group, and there was no significant difference between the groups (p=0.122). In all patients, symptoms of irritability improved with dose reduction or discontinuation of PER.
Conclusions:
Our results showed that starting with 1mg did not significantly change the incidence of irritability caused by PER. However, in the 1 mg group, we started with 1 mg of PER, then increased the dose to 2 mg, and increased the dose by 2 mg thereafter as we did in the 2 mg group. This could have affected affect the result of our study. Further study with slower titration speed might be needed to improve the incidence of irritability in PER.
Funding:
There was no funding for this study. Dr. Watanabe has received honoraria lecture fee from DAIICHI SANKYO Co Ltd., UCB Japan Co. Ltd. and EISAI Co. Ltd.