<prompt> A psychiatric patient on regular treatment had his routine check-up. His fundus shows the below finding. The most probable drug implicated is Pigmented retinal epitheliumThioridazoneHaloperidolChlorpromazineClozapine  <response>: Irreversible retinal pigmentation is associated with the use of thioridazine at dosages above 1000mgdayhence 800day nocturnal confusion is an early sign of this adverse effect. Reference: P.3121 chap. 31.17First-Generation Antipsychotics Kaplan Sadocks Comprehensive Textbook of Psychiatry, 9th Edition 