Canada's crackdown on poppers and trends in crystal methamphetamine use among sexual and gender diverse men: a secondary data analysis.

BACKGROUND: Poppers (alkyl nitrites) relax smooth muscle when inhaled and can enhance comfort and pleasure during anal intercourse. In 2013, Health Canada cracked down on poppers products. As crystal methamphetamine (CM) has previously been observed as a substitute for poppers under conditions of restricted poppers access, we assess poppers and CM use among sexual and gender diverse men in Canada before and after 2013. METHODS: We used 26,918 observations from the 2012, 2015 and 2019 cycles of Sex Now, a Canadian survey of sexual and gender diverse men. Logistic regression was used to identify factors associated with CM use and compare CM use before and after the crackdown. Modified Poisson regression with robust variance was used as an approximation to log-binomial regression to assess levels of poppers use during pre- and post-crackdown periods. RESULTS: Recent CM use was associated with 8.69 times higher odds of using poppers (95%CI: 7.30-10.3), and 4.68 times higher odds of living with HIV (95%CI: 3.98-5.50). Being over 25, being single, having experienced anti-2S/LGBTQIA+ violence, living in more urban settings, and having lower annual income were associated with higher odds of CM use. Risk of CM use was higher in the post-crackdown period. Concurrent use of poppers and CM increased in the post-crackdown period while the prevalence of poppers use decreased. CONCLUSIONS: Poppers use continues despite the crackdown. It is possible prohibitive poppers regulation may cause unintended harm by driving substitution of more harmful substances including CM, however more research is needed to understand this possibility.