Abstract
BackgroundOlanzapine 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.MethodsCases 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).ResultsA 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).ConclusionsThe 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s12888-015-0450-9) contains supplementary material, which is available to authorized users.
Highlights
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
Sixty-six PDSS events were reported in 63 patients, indicating that PDSS occurred with approximately 0.07% of injections, and in 1.03% of patients in these post-marketing studies (Table 1)
A total of 272 PDSS events were reported in 270 patients, indicating that PDSS occurred with approximately 0.07% of injections and in 0.46% of patients according to spontaneous reports (Table 1)
Summary
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. Clinical trials have shown that olanzapine LAI has comparable efficacy and safety to oral olanzapine with the exception of adverse events related to the route of administration [3,4,5] In these trials, olanzapine LAI was associated with a cluster of symptoms related to postinjection delirium and/or excessive sedation in a small. Bushe et al BMC Psychiatry (2015) 15:65 number of patients (~2%) [5,6,7,8] These symptoms, collectively referred to as post-injection syndrome or postinjection delirium/sedation syndrome (PDSS), have been fully defined (see list below) and appear to be consistent with symptoms associated with an oral olanzapine overdose [5,6]. For a clinical diagnosis of PDSS, the following criteria must be met [6]: 1. One or both of the conditions listed in (a) and (b): (a) A minimum of 1 sign or symptom from at least 3 of the following symptom clusters consistent with olanzapinea overdose with one or more of at least moderate severity: Sedation/somnolence Delirium/confusion/disorientation/other cognitive impairment Dysarthria/other speech impairment Ataxia/other motor impairment Extrapyramidal symptoms Agitation/irritability/anxiety/restlessness Dizziness/weakness/general malaise Seizure (b)Any 1 of the following signs and symptoms: Unarousable Unconscious Stuporous Comatose
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