  The complex unfolding of the US opioid epidemic in the last 20 years has been
the subject of a large body of medical and pharmacological research, and it has
sparked a multidisciplinary discussion on how to implement interventions and
policies to effectively control its impact on public health. This study
leverages Reddit as the primary data source to investigate the opioid crisis.
We aimed to find a large cohort of Reddit users interested in discussing the
use of opioids, trace the temporal evolution of their interest, and extensively
characterize patterns of the nonmedical consumption of opioids, with a focus on
routes of administration and drug tampering. We used a semiautomatic
information retrieval algorithm to identify subreddits discussing nonmedical
opioid consumption, finding over 86,000 Reddit users potentially involved in
firsthand opioid usage. We developed a methodology based on word embedding to
select alternative colloquial and nonmedical terms referring to opioid
substances, routes of administration, and drug-tampering methods. We modeled
the preferences of adoption of substances and routes of administration,
estimating their prevalence and temporal unfolding, observing relevant trends
such as the surge in synthetic opioids like fentanyl and an increasing interest
in rectal administration. Ultimately, through the evaluation of odds ratios
based on co-mentions, we measured the strength of association between opioid
substances, routes of administration, and drug tampering, finding evidence of
understudied abusive behaviors like chewing fentanyl patches and dissolving
buprenorphine sublingually. We believe that our approach may provide a novel
perspective for a more comprehensive understanding of nonmedical abuse of
opioids substances and inform the prevention, treatment, and control of the
public health effects.
