[Fatal poisonings with antidepressive drugs and neuroleptics. Analysis of a correlation with prescriptions in Vienna 1991 to 1997].

As a result of the increasing use of selective serotonin reuptake inhibitors (SSRI), the number of antidepressants (AD) prescribed in Vienna doubled from 1991 to 1997. In the same period, autopsies and chemical analyses performed at the Institute of Forensic Medicine, University of Vienna, revealed a total of 164 fatal intoxications by means of AD. In this study, the number of fatal intoxications per million defined daily doses prescribed was determined and referred to as the fatal toxicity index (f-index). For both single- and multiple-substance intoxications, it proved to be significantly (p < 0.001) lower with SSRI than with tricyclic antidepressants (TCA). Single-substance intoxications (n = 30) were seen exclusively in TCA. Concerning neuroleptics (NL), the increase in prescriptions observed in the study period (plus 30%) was less pronounced, and they were found to be involved in 85 fatal intoxications. Also in NL, those of the tricyclic type (TCNL) showed a significantly (p < 0.001) higher f-index than other groups. Out of a total of 17 single-substance intoxications, 14 were caused by TCNL and none by butyrophenones or haloperidol. The present study demonstrates that the prescription of TCA or TCNL involves a relatively high risk of fatal intoxication.