Olanzapine poisoning in patients treated at the National Poison Control Centre in Belgrade, Serbia in 2017 and 2018: a brief review of serum concentrations and clinical symptoms

Abstract

Olanzapine is a thienobenzodiazepine class antipsychotic that strongly antagonises the 5-HT2A serotonin receptor, but acute poisonings are reported rarely. Symptoms of an overdose include disorder of consciousness, hypersalivation, myosis, and coma. Serum concentration higher than 0.1 mg/L is toxic, while concentration above 1 mg/L can be fatal. Here we report key data about 61 patients admitted to the National Poison Control Centre in Belgrade, Serbia over olanzapine poisoning in 2017 and 2018. The ingested doses ranged from 35 to 1680 mg, and time from ingestion to determination from two to 24 hours. In 34 patients olanzapine serum concentrations were in the therapeutic range and in 27 in the toxic range. In five patients they were higher than fatal, but only one patient died. The most common symptoms of poisoning were depressed consciousness (fluctuating from somnolence to coma), tachycardia, hypersalivation, hypotension, myosis, and high creatine kinase. All patients but one recovered fully after nonspecific detoxification and symptomatic and supportive therapy.

Case Series Profile of Olanzapine Post-Injection Delitrium/Sedation Syndrome

“…Complications like urinary retention, rhabdomyolysis and fever appear to be less frequent. Moreover, the distribution of anti-cholinergic over anti-dopaminergic symptoms mimics that of oral olanzapine overdose 5,6 adding further support to the theorised pathophysiology of PDSS being that of premature rapid dissolution of the salt intravascularly 2 .…”

“…This is supported by the fact that PDSS is primarily reported amongst patients who received olanzapine palmoate depot injection and not other long acting injectables 4 . In addition, the syndrome's presentation with anticholinergic and anti-dopaminergic symptoms is similar to oral olanzapine overdose and high serum olanzapine levels occur in those who develop it 5,6 . Current management for this condition is limited and involves supportive care and benzodiazepines for agitation 7 .…”

Case series profile of olanzapine post‐injection delirium/sedation syndrome

“…Complications like urinary retention, rhabdomyolysis and fever appear to be less frequent. Moreover, the distribution of anticholinergic over antidopaminergic symptoms mimics that of oral olanzapine overdose, 5,6 with rhabdomyolysis found in severe olanzapine poisoning cases, 5 adding further support to the theorised pathophysiology of PDSS being that of premature rapid dissolution of the salt intravascularly 3 …”

“…This is supported by the fact that PDSS is primarily reported amongst patients who received olanzapine pamoate depot injection and not other long‐acting injectables 4 . In addition, the syndrome's presentation with anticholinergic and anti‐dopaminergic symptoms is similar to oral olanzapine overdose and high serum olanzapine levels occur in those who develop it 5,6 . Current management for this condition is limited and involves supportive care and sedation for severe agitation 7,8 .…”

“… 4 In addition, the syndrome's presentation with anticholinergic and anti‐dopaminergic symptoms is similar to oral olanzapine overdose and high serum olanzapine levels occur in those who develop it. 5 , 6 Current management for this condition is limited and involves supportive care and sedation for severe agitation. 7 , 8 We aimed to investigate characteristics of olanzapine PDSS including onset, clinical features and treatment approach.…”