Sex Differences in Methamphetamine Mortality in the United States: Heroin and Fentanyl Coinvolvement, 1999-2021.

Introduction: Prepandemic data suggests that methamphetamine-related mortality and opioid coinvolvement have been increasing in the U.S. However, there was a staggering number of U.S. drug overdose deaths in 2020 and 2021, particularly among males. An updated examination of sex-specific trends in methamphetamine-related mortality, the extent to which these deaths may be driven by the heroin and fentanyl coinvolvement, and whether this coinvolvement might explain the disproportionate number of male methamphetamine deaths is warranted.

Methods: The authors leveraged final and provisional data from the CDC WONDER multiple causes of death database to examine deaths involving methamphetamine (i.e., psychostimulants with abuse potential, ICD-10 code T43.6) and methamphetamine-related deaths that coinvolved heroin and/or synthetic opioids excluding methadone (ICD-10 code T40.4; e.g., fentanyl) among U.S. residents aged 15-74 years. The authors plotted age-adjusted methamphetamine mortality rates by sex and year and quantified the proportion of deaths with heroin/synthetic opioid coinvolvement. Finally, they used Joinpoint regression models to quantify sex-specific trends in methamphetamine mortality and the proportion of deaths with heroin and/or synthetic opioid coinvolvement.

Results: From 1999 to 2021, the methamphetamine-related mortality rate increased 58.8-fold among males (0.33 per 100,000 to 19.74 per 100,000) and 65.3-fold among females (0.12 per 100,000 to 7.96 per 100,000), with the greatest increases occurring between 2019 and 2021. The proportion of these deaths that coinvolved heroin and/or synthetic opioids increased among both males (13.1% to 61.5%) and females (7.7% to 63.1%) from 1999 to 2021.

Conclusions: Increasing methamphetamine-related mortality among males and females has been accompanied by a dramatic increase in the proportion of heroin and/or synthetic opioid coinvolvement among both sexes. Robust harm reduction efforts are needed to mitigate these increases, particularly for people who couse stimulants and opioids.