Clinical Course and Discontinuation of Olanzapine Long-Acting Injectable: A Retrospective Case Series Including a Case of Post-Injection Delirium/Sedation Syndrome
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background: Olanzapine long-acting injectable (OLAI; olanzapine pamoate) is an effective depot antipsychotic option for schizophrenia-spectrum illness, but its clinical uptake is limited by the required post-injection observation period and by post-injection delirium/sedation syndrome (PDSS). Real-world descriptive data on outcomes for patients started on OLAI remain limited. Methods: A retrospective descriptive case series was conducted on outpatients at three behavioral health clinics who had been prescribed OLAI. Data collected included baseline demographic and diagnosis, medication trials including oral and OLAI treatment course, side effects and hospitalizations. Results: Thirty patients with a documented OLAI prescription were included in the study. They were predominantly male (20, 66.7%), with median age of 36.2 years and mostly treated at an Assertive Community Treatment (ACT) clinic, (21, 70.0%). Primary diagnoses were schizophrenia (15, 50.0%) or schizoaffective disorder (13, 43.3%). Most patients had prior exposure to another LAI (23, 76.7%), and oral olanzapine use was first started during hospitalization in a majority of cases (24, 80.0%). OLAI was discontinued in 19 patients (63.3%); documented reasons included refusal/nonadherence, perceived lack of efficacy, adverse effects, transfer of care, monitoring burden, operational barriers, medication shortage, and PDSS. Conclusions: PDSS was uncommon but clinically significant and occurred after extended OLAI tolerability was established, with immediate sedation/altered mental status requiring emergency evaluation and several days of delirium. The most visible non-PDSS barriers were discontinuation, nonadherence/refusal, 3-hour monitoring burden, medication shortage, and heterogeneous tolerability complaints. These data support descriptive reporting and careful local protocol review rather than risk-factor inference.
Source: Psychopharmacology Bulletin
DOI: 10.64719/pb.21594
Institutions: Creighton University, Valleywise Health
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7225202209