BACKGROUND Long-acting injectable (LAI) antipsychotics are one of the forms of therapy for severe mental illness. Post-injection delirium/sedation syndrome (PDSS) is a very rare but serious adverse effect following the application of an olanzapine in a long-acting form. The most common symptoms of the syndrome are sedation, delirium, dysarthria, ataxia, extrapyramidal symptoms, agitation, dizziness, or seizure. The predispositions, prevention, and exact mechanism of PDSS remain unclear. CASE REPORT We present a case report of a 30-year-old male patient experiencing PDSS, including the main symptoms of PDSS, diagnostic methods, olanzapine plasma concentrations, therapeutic process, and outcome. We then include a follow-up of the patient 2.5 years later. The patient did not have any long-term damage, had no disabilities, and no post-traumatic stress disorder following the event. We include information about his current medications, further use of LAI antipsychotics, and update about his everyday life. CONCLUSIONS PDSS is a life-threatening condition clinicians must be aware of, and the easiest precaution is a 3-h observation after the application of an injection. Because the predispositions, prevention, and exact mechanism of PDSS remains unclear, it is very important to report the rare cases of PDSS and conduct further research for the safety of our patients. The follow-up of the patient showed that the patient is doing well, he has no post-traumatic stress disorder following the event, and he did continue to use LAI antipsychotic medication.

Department of Psychiatry 1st Faculty of Medicine Charles University and General University Hospital Prague Prague Czech Republic

Department of Psychiatry Krajska zdravotni a s Most Hospital Most Czech Republic

Zobrazit více v PubMed

Leucht S, Tardy M, Komossa K, et al. Antipsychotic drugs versus placebo for relapse prevention in schizophrenia: A systematic review and meta-analysis. Lancet. 2012;379(9831):2063–71. PubMed

Kishimoto T, Nitta M, Borenstein M, et al. Long-acting injectable versus oral antipsychotics in schizophrenia: A systematic review and meta-analysis of mirror-image studies. J Clin Psychiatry. 2013;74(10):957–65. PubMed

Taipale H, Mittendorfer-Rutz E, Alexanderson K, et al. Antipsychotics and mortality in a nationwide cohort of 29,823 patients with schizophrenia. Schizophr Res. 2018;197:274–80. PubMed

McDonnell DP, Detke HC, Bergstrom RF, et al. Post-injection delirium/sedation syndrome in patients with schizophrenia treated with olanzapine long-acting injection, II: Investigations of mechanism. BMC Psychiatry. 2010;10:45. PubMed PMC

Heres S, Kraemer S, Bergstrom RF, Detke HC. Pharmacokinetics of olanzapine long-acting injection: The clinical perspective. Int Clin Psychopharmacol. 2014;29(6):299–312. PubMed PMC

Detke HC, McDonnell DP, Brunner E, et al. Post-injection delirium/sedation syndrome in patients with schizophrenia treated with olanzapine long-acting injection, I: Analysis of cases. BMC Psychiatry. 2010;10:43. PubMed PMC

Hiemke C, Baumann P, Bergemann N, et al. AGNP consensus guidelines for therapeutic drug monitoring in psychiatry: Update 2011. Pharmacopsychiatry. 2011;44(6):195–235. PubMed

SPC Zypadhera. https://www.ema.europa.eu/en/documents/product-information/zypadhera-epar-product-information_en.pdf [checked 19.06.2022]

Meyers KJ, Upadhyaya HP, Landry JL, et al. Postinjection delirium/sedation syndrome in patients with schizophrenia receiving olanzapine long-acting injection: Results from a large observational study. BJPsych Open. 2017;3(4):186–92. PubMed PMC

Bushe CJ, Falk D, Anand E, et al. Olanzapine long-acting injection: A review of first experiences of post-injection delirium/sedation syndrome in routine clinical practice. BMC Psychiatry. 2015;15:65. PubMed PMC

Garg S, Gupta D, Rakesh K, Tikka SK. Delayed onset postinjection delirium/ sedation syndrome associated with olanzapine pamoate: A case report. J Clin Psychopharmacol. 2019;39(5):523–24. PubMed