Refractory Psychosis After Carbon Monoxide Poisoning: a Case Report.

We report a case of refractory psychosis after carbon monoxide poisoning in a 65-year-old woman who attempted suicide by charcoal burning in 2018. On discharge from hospital, she was bedbound, tube-fed, and had limited verbal output. In early 2019, she was able to resume oral feeding and her physical condition improved. However, she started to have paranoid ideas and auditory hallucinations. She was diagnosed as having organic brain syndrome and was prescribed with quetiapine 300 mg every night. Because of the poor clinical response, quetiapine was switched to olanzapine 20 mg every night and augmented with amisulpride and valproate sodium. However, she remained distressed, psychotic, and suicidal. She was then prescribed with clozapine 300 mg every night. Her symptoms improved despite residual auditory hallucinations remained, but she was less distressed about them.