Psychiatry Investig.  2019 Apr;16(4):279-284. 10.30773/pi.2018.12.16.

Relationship between Clozapine-Induced Electroencephalogram Abnormalities and Serum Concentration of Clozapine in Japanese Patients with Treatment-Resistant Schizophrenia

• Kikuchi YS
• Kanbayashi T
• Shimizu T

• KMID: 2447785
• DOI: http://doi.org/10.30773/pi.2018.12.16

Abstract

OBJECTIVE
The objective of this study was to investigate the relationship between the serum concentration of clozapine (C-CLZ), N-desmethylclozapine (N-CLZ) and the daily dose of CLZ (D-CLZ), and the relationships among CLZ and electroencephalogram (EEG) abnormalities.
METHODS
Twenty-eight patients were recruited to this study, but 8 patients were excluded because clozapine was discontinued before the post-treatment measurement of EEG or C-CLZ. Ultimately, 20 patients (6 men, 14 women) with an average age of 36 years were enrolled. The subjects were divided into EEG normal and abnormal groups. C-CLZ and N-CLZ were measured at 4, 12, 26, and 52 weeks after initiating CLZ administration.
RESULTS
All patients had normal baseline EEG signals, and 8 patients showed EEG abnormalities later. There were significant correlations between C-CLZ and D-CLZ, and between N-CLZ and D-CLZ. The C-CLZ/D-CLZ, N-CLZ/D-CLZ, and C-CLZ/N-CLZ ratio were not significantly different between the EEG normal and EEG abnormal groups. The EEG abnormal group had significant higher proportion of patients with high intra-individual variability in their C-CLZ/D-CLZ ratio.
CONCLUSION
There is no relationship between C-CLZ and EEG abnormalities. However, patients with high intra-individual variability in their C-CLZ/D-CLZ ratio had greater possibility of exhibiting EEG abnormalities.

Keyword

Serum clozapine concentration; Electroencephalography abnormalities; Treatment-resistant schizophrenia

MeSH Terms

Asian Continental Ancestry Group*
Clozapine*
Electroencephalography*
Humans
Male
Schizophrenia*
Clozapine