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

Abstract

BackgroundDepot 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.MethodsData 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).ResultsThe 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.ConclusionsResults 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s12888-015-0669-5) contains supplementary material, which is available to authorized users.

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

“…The clinical presentation and resolution of PDSS were consistent with previously published data. 3 , 4 , 11 , 12 Based on 45 of 46 observed events in this study with time-to-onset and time-to-recovery information, 91.1% occurred within 1 h of injection and 95.6% resolved within 72 h. Time to onset was consistent with a recent publication reporting that 90% of 323 post-marketing PDSS events occurred within 1 h of injection. 8 PDSS events were more likely to occur within the first hour of injection in post-marketing experience compared with in clinical trials, where approximately 80% of 30 PDSS events occurred within 1 h. 4 This reduced time to onset could reflect increased awareness of PDSS signs and symptoms and successful risk-minimisation activities, such as product labelling and the Healthcare Awareness Programme.…”

Postinjection Delirium/Sedation Syndrome with Olanzapine Depot Injection

“…[ 10 ] The incidence of PDSS is seen in approximately 0.05–0.07% of injections and 0.75–1.4% of patients. [ 11 12 13 ] Here we present a case of PDSS and discuss various clinically important aspects.…”