Suicide Prevention

Risk of Drug Overdose Lethality Ranked by Drug Class

Risk that an overdose would be fatal was highest in instances involving opioids or barbiturates, according to a recent analysis of the lethality of intentional overdoses between various classes of drugs.

The researchers conducted a cross-sectional study using data from state censuses and national samples including 421,466 suicidal drug overdoses. Rather than condense drug poisoning into a lumped category as previous analyses have, the researchers sought to investigate the risk of lethality by drug class.

“We estimated what proportion of people who died of suicidal acts involving specific drugs may have survived their overdose if their drug mix had omitted a given drug class. For example, we analyzed what portion of completed suicides that involved opioids might not have been fatal if opioids were not involved,” the researchers wrote.

Overall, 21,594 deaths resulted from the studied 421,466 drug poisoning suicidal acts. Of these deaths, 19.6% to 22.5% involved benzodiazepines, and 15.4% to 17.3% involved opioids. Opioids were associated with a 5.20 times greater relative risk (RR) of suicide completion than the mean for suicide involving other drug classes. Opioids were followed by barbiturates (RR, 4.29; 95% CI, 3.35-5.45), antidepressants (RR, 3.22; 95% CI, 2.95-3.52), and antidiabetics (RR, 2.57; 95% CI, 1.94-3.41). Calcium channel blockers were also found to have a high RR (2.24; 95% CI, 1.89-2.61) when using the updated toxin diagnosis coding in International Statistical Classification of Diseases and Related Health Problems, Tenth Revision.

“These findings suggest that preventing access to lethal means for patients at risk for suicide should extend to drugs with high case fatality rates. Blister packing and securely storing lethal drugs seems advisable,” the authors concluded.

—Michael Potts

Miller TR, Swedler DI, Lawrence BA, et al. Incidence and lethality of suicidal overdoses by drug class [published online March 23, 2020]. JAMA Netw Open. 2020;3(3):e200607. doi:10.1001/jamanetworkopen.2020.0607