Delirium with anticholinergic symptoms after a combination of paliperidone and olanzapine pamoate in a patient known to smoke cannabis: an unfortunate coincidence.

We report a case of delirium with anticholinergic symptoms in a 19-year-old female patient with schizophrenia. On the day the symptoms emerged, the patient received olanzapine long-acting injection and a higher dose of paliperidone. We observed symptoms ranging from confusion to delirium as well as some anticholinergic symptoms. The delirium lasted 24 hours and was managed by intravenous fluid substitution and oral benzodiazepines. Olanzapine pamoate, paliperidone and cannabis are central nervous system (CNS) depressants, and their combination can increase the risks of CNS depression. In this case report, we review the symptoms of delirium in a case of antipsychotic overdose and provide general guidelines for managing these symptoms. We also review possible complications in combined use of cannabis, olanzapine and paliperidone.