Category: Addictive Behaviors
Among those with an opioid use disorder, heroin use is associated with higher clinical severity, worse treatment outcomes, and increased overdose risk relative to use of prescription opioids (POs) alone. Qualitative and population-level data indicate that most new heroin users first misused POs, highlighting the importance of understanding the progression from POs to heroin to inform prevention and treatment efforts for reducing heroin initiation. We aim to characterize opioid use trajectories among 16 adults (age = 33.3 ± 11.4 years; 43.8% female) enrolled in a clinical trial for the treatment of opioid use disorder. Participants completed a battery of self-report and interviewer-administered measures, which were utilized to describe opioid use trajectories. Overall, 4 participants had only used POs, 2 participants had only used heroin, and 10 participants had histories of both PO and heroin use. The average age of PO initiation was 21.3 ± 7.8 years; participants first received POs from a variety of sources, including from a doctor for a legitimate reason (n = 4), from a dealer (n= 4), and “someone gave them to me” (n = 4). Of the 10 participants who had a history of both PO and heroin use, all reported PO use before heroin initiation. Participants initiated heroin approximately 4.9 ± 4.9 years after PO initiation. The average age of heroin initiation was 24.5 ± 3.5 years among those who had only used heroin and 24.4 ± 6.1 years among those who initiated heroin use following PO use. The most commonly reported reasons for heroin initiation were: cheaper than POs (38.1%), easier to obtain than POs (33.3%), and peer influence (28.6%). Among those with a history of heroin use, all but one reported using intravenous (IV) heroin use. Two participants initiated heroin use with IV use, and the other 9 reported an average of 8.3 ± 11.3 months between heroin initiation and IV heroin use. These results are consistent with population-level data suggesting that many heroin users initiate opioid use with POs. Notably, there was an average of 5 years (range = 1 month to 15 years) from the initiation of PO use to heroin use, suggesting that there may be a window in which to intervene to prevent the initiation of heroin use. The rapid transition from heroin initiation to IV use indicates that disorder severity worsens quickly once heroin is initiated. These results further highlight the importance of intervening to prevent heroin initiation among PO users. Prospective studies should examine risk factors (e.g., sociodemographic and drug use characteristics, affective vulnerabilities) for heroin initiation among those with PO use to inform the development of targeted interventions for this period.