Substances used in completed suicide by overdose in Toronto: an observational study of coroner's data

To identify the substances used by people who die from suicide by overdose in Toronto and to determine the correlates of specific categories of substances used.

Coroner's records for all cases of suicide by overdose in Toronto, Ontario, during a 10-year period (1998 to 2007) were examined. Data collected included demographic data, all substances detected, and those determined by the coroner to have caused death. Logistic regression analyses were used to examine demographic and clinical factors associated with suicide by different drug types.

There were 397 documented suicides by overdose (mean age 49.1 years, 50% female). Most substances detected were psychotropic prescription medications (n = 245), followed by other prescription medications (n = 143) and over-the-counter (OTC) medications (n = 83). More than one-half of all suicides by overdose were determined to have only one specific substance as the cause of death (n = 206). In suicides where only one class of substance was present in lethal amounts, OTC medication (n = 48), opioid analgesics (n = 44), and tricyclic antidepressants (n = 44) were most common.

Suicides by overdose involved the use of different classes of substances, including psychotropic prescription medication, other prescription medications, as well as OTC medications. Physicians and pharmacists should be aware of commonly used prescription and OTC medications in overdose and exercise increased vigilance in prescribing or dispensing them to at-risk patients.