AUTHOR=Torrico Tyler J. 

TITLE=The pathophysiology of rapid fluctuations in mental status associated with olanzapine: A case report

JOURNAL=Frontiers in Psychiatry

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2022.1028350

DOI=10.3389/fpsyt.2022.1028350

ISSN=1664-0640

ABSTRACT=Background
Olanzapine toxicity has reports of a rare but specific phenomenon characterized by rapid fluctuations between somnolence and agitation, which has been referred to as “agitation despite sedation.” A similar phenomenon is observed as an adverse reaction of the long-acting injectable olanzapine formulation, which has been referred to as “delirium/sedation syndrome”. 
Case Presentation
This case report describes a 48-year-old male diagnosed with schizophrenia who experienced rapid fluctuations between somnolence and agitation during a cross-titration of olanzapine to clozapine. The patient had normal serum levels of both medications and the symptoms resolved with discontinuation of olanzapine. 
Conclusions
Rapid fluctuations in mental status between somnolence and agitation are not clearly described amongst other antipsychotics, and it is possible that this phenomenon may be specific to olanzapine. The findings of this case report suggest that this phenomenon is likely the result from the oversaturation of (H1) and (M1) receptors.