Olanzapine long-acting injection: a review of first experiences of post-injection delirium/sedation syndrome in routine clinical practice.

BACKGROUND: Olanzapine long-acting injection (LAI) for the treatment of schizophrenia was associated with a cluster of symptoms termed post-injection delirium/sedation syndrome (PDSS) in a small percentage (~2%) of patients during clinical trials. The objective of this analysis was to evaluate the rate and clinical characteristics of PDSS since olanzapine LAI entered commercial use. METHODS: Cases of PDSS were identified from all reported adverse events during worldwide commercial use of olanzapine LAI through to 1 March 2014. Data sources included two ongoing post-marketing safety studies as well as spontaneously reported adverse events from routine clinical practice over a 5-year period (1 March 2009 to 1 March 2014). RESULTS: A total of 338 PDSS events were identified. Of these, 91% occurred within 1 hour of injection, and 52% of these occurred within 15 minutes. None of the PDSS events in this analysis were fatal, and most resolved within 72 hours. The most common symptoms (occurring in >30% of cases) were sedation (61%), confusion (56%), dysarthria (54%), somnolence (46%), dizziness (45%) and disorientation (35%). Overall, PDSS occurred with approximately 0.07% of injections and in 0.46-1.03% of patients (reporting and incidence rates from spontaneous reports and post-marketing safety studies, respectively). CONCLUSIONS: The PDSS events reported during routine clinical use of olanzapine LAI are generally similar in incidence and presentation to those reported in clinical trials. Caution should be applied when interpreting spontaneously reported rates of adverse events, however, due to potential under-reporting. Implemented risk-minimisation activities may contribute substantially to the identification and appropriate management of patients with PDSS in clinical practice.

Baseline characteristics and hospitalizations in patients with schizophrenia receiving olanzapine long-acting injection: an interim analysis from a non-interventional, prospective observational safety study.

BACKGROUND: Depot antipsychotics are a treatment option for medication nonadherence in patients with schizophrenia. Nonadherence can lead to increased relapse and hospitalization rates. This article reports hospitalization data before and after initiation of olanzapine long-acting injection (LAI), a depot antipsychotic. METHODS: Data were assessed from an ongoing, multinational, prospective, observational post-authorisation safety study being conducted to evaluate post-injection delirium/sedation syndrome (PDSS), an adverse reaction that can occur following injection of olanzapine LAI. Eligible patients were aged ≥18 years, diagnosed with schizophrenia, were prescribed olanzapine LAI, and lived outside the United States. Psychiatric hospitalization and medication data were collected retrospectively for the 6-month period before study entry and prospectively throughout the study. Paired t-tests and McNemar's tests were used to assess changes in hospitalization incidence and duration. Stepwise Cox proportional hazards models assessed factors associated with hospitalizations. Analyses were based on data from the first 3 years of the continuously enrolling study (N = 668). RESULTS: The average duration of olanzapine LAI exposure for all patients was 0.768 years. Of the 529 patients who received at least 1 injection of olanzapine LAI and were not hospitalized at study entry, 8.1% had at least 1 subsequent psychiatric hospitalization with a mean duration of 2.0 days. Of the 288 patients who had a >6-month follow-up, 8.3% had at least 1 post-baseline psychiatric hospitalization with a mean duration of 2.3 days. The incidence of hospitalizations in the 6-month period after treatment was significantly lower than that in the 6-month period prior to treatment (8.3 vs 32.6%, respectively; P < 0.001). Furthermore, mean hospitalization duration decreased from 11.5 days in the 6-month period before treatment to 2.3 days in the 6-month period after treatment (P < 0.001). Psychiatric hospitalization in the prior 12 months (P < 0.0001) and recreational drug use within 24 h of baseline visit (P = 0.015) were identified as potential predictors of time to first psychiatric hospitalization after beginning to take olanzapine LAI. At the time of interim analysis, 5 PDSS events had occurred, which was too few for a full analysis of those events. CONCLUSIONS: Results indicate a significant reduction in the incidence and days of hospitalization from the 6-month period before to the 6-month period after olanzapine LAI initiation, which suggests reduced relapse and hospitalization during treatment. Results should be interpreted with caution due to the observational nature of the study and use of retrospective baseline data.

Postinjection delirium/sedation syndrome in patients with schizophrenia receiving olanzapine long-acting injection: results from a large observational study.

BACKGROUND: Postinjection delirium/sedation syndrome (PDSS) has been reported uncommonly during treatment with olanzapine long-acting injection (LAI), a sustained-release formulation of olanzapine. AIMS: The primary aim of the study was to estimate the incidence per injection and per patient of PDSS events in adult patients with schizophrenia who were receiving olanzapine LAI in real-world clinical practice. Secondary aims were to further characterise the clinical presentation of PDSS events, to identify potential risk factors associated with PDSS events and to characterise hospitalisations at baseline and post-baseline. METHOD: A prospective observational study of adult patients with schizophrenia receiving olanzapine LAI from 24 countries. Data were collected on patient characteristics, olanzapine LAI treatment and any adverse events (AEs). All AEs were reviewed and adjudicated for PDSS using predetermined criteria. RESULTS: There were 46 confirmed PDSS events (0.044% of the 103 505 injections) in 45 patients (1.17% of the 3858 patients). Based on 45 confirmed events with time-to-onset information, 91.1% (n=41) occurred within 1 h of injection. Time-to-recovery from the event was within 72 h for 95.6% of patients (range 6 h to 11 days). Risk factors for PDSS (per-injection) included high dose (odds ratio (OR)high/low=3.95; P=0.006) and male gender (ORfemale/male=0.42; P=0.017). CONCLUSIONS: Results of this study confirm previously reported PDSS rates, time to onset and recovery, and the severity of PDSS events, and suggest that higher doses and male gender are potential risk factors associated with PDSS. DECLARATION OF INTEREST: All authors are full-time employees and hold stock/stock options in Eli Lilly, which funded this study. This post-authorisation safety study (PASS) was proposed by Eli Lilly when submitting the original marketing authorisation application for olanzapine LAI in 2007. The protocol and final study report for this European Union regulatory commitment are publicly accessible via the European Network of Centres for Pharmacoepidemiology and Pharmacovigilance (ENCePP) European Union PASS Register (www.encepp.eu/encepp/viewResource.htm?id=16847). The current manuscript describes the results within the final study report. COPYRIGHT AND USAGE: © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.