Objectives: Self-poisoning is the most common suicide method in non-lethal suicide attempts and the third most frequent in fatal suicides. Psychoactive drugs are often used for intentional self-poisoning. While poisons centre data typically focus on survived suicide attempts and underrepresent fatal self-poisoning, medical examiner reports give insight into suicide deaths. To close this gap, we combined and compared data sets from both sources, assessing the mortality of psychotropic drugs used for self-poisoning.
Methods: Anonymized cases of self-poisoning with suicidal intention from 2000 to 2010 were extracted from the national poisons centre case database and compared with cases of suicide documented in the project "Suicides, a national survey". All cases with single substance exposure to a psychoactive drug (antidepressants, mood stabilizers, antipsychotics, sedatives) were included in the analyses. Opioids, over-the-counter- and illicit- drugs were excluded from the analysis. A mortality index was calculated by the ratio of the number of suicides and the sum of all (lethal and non-lethal) suicide attempts.
Results: Tricyclics had a higher mortality rate than other antidepressants. Among the sedatives, zolpidem was found to have a higher mortality index compared to benzodiazepines. Clozapine and levomepromazine were found to be the most lethal antipsychotics. Non-lethal suicide cases with single substance exposure (n = 4697) diminished as age increased, while the rate of suicide cases (n = 165) was higher in elderly subjects (>65 years of age, p < 0.001).
Conclusion: In summary, our findings confirm previous study results on the relative toxicity of distinct classes of psychotropic drugs. In this comprehensive analysis of a national cohort lorazepam had a lower mortality rate compared to other sedatives.
Copyright © 2019. Published by Elsevier Inc.