Antipsychotic-Related Fatal Poisoning, England and Wales, 1993-2019: The Impact of Second-Generation Antipsychotics.

Background: Deaths from antipsychotic (AP) poisoning have increased in England and Wales despite restriction of the use of thioridazine in 2000.

Methods: We analyzed data from the Office for National Statistics drug-related death database, England and Wales, 1993-2019, to investigate fatal AP poisoning.

Results: There were 2286 deaths (62% male patients). Annual numbers of intentional AP-related fatal poisonings (suicides) were relatively stable (1993, 35; 2019, 44; median, 44; range, 30-60). Intentional overdose deaths involving clozapine (96 male, 25 female) increased from 1 in 1994 to 5 in 2003 and have since remained relatively constant (median, 6; range, 3-10 per annum). Unintentional second-generation AP-related fatal poisonings have increased steadily since 1998, featuring in 828 (74%) of all unintentional, AP-related fatal poisonings in the period studied (2019, 89%). There were 181 unintentional clozapine-related deaths, (107 [59%] alone without other drugs ± alcohol) as compared with 291 quetiapine-related deaths (86 [30%] alone without other drugs ± alcohol) and 314 unintentional olanzapine-related deaths (77 [25%] alone without other drugs ± alcohol). Some 75% of all unintentional clozapine- and olanzapine-related deaths were of male patients (78% and 73%, respectively) as compared with 58% of unintentional quetiapine-related fatal poisonings. Clozapine now features prominently in intentional and in unintentional AP-related fatal poisoning in England and Wales. Deaths of male patients predominate in both categories. There were also 77 and 86 deaths attributed to unintentional poisoning with olanzapine and with quetiapine, respectively, in the absence of other drugs.

Conclusions: More effort is needed to prevent unintentional deaths not only from clozapine but also from olanzapine and quetiapine.