Factors associated with illicit methadone injecting in a Canadian setting

Abstract

Background and Objectives While methadone is well established as an evidence-based treatment for opioid use disorder, safety concerns persist regarding its diversion. We examine the prevalence of and risk factors associated with injection of methadone in an urban population. Methods Between December 2005 and November 2013, data were derived from two open prospective studies of persons who inject drugs (PWID) in Vancouver, Canada. Generalized estimating equations (GEE) logistic regression was used to determine factors independently associated with illicit methadone injecting. Results During the study, 1911 individuals (34% women) were recruited; 134 (7%) participants reported methadone injecting at least once. In multivariable analysis, Caucasian ethnicity [adjusted odds ratio (AOR) = 1.90, 95% confidence interval (CI) = 1.20 – 3.00]; homelessness (AOR = 1.46, 95% CI = 1.09 – 1.95); drug dealing (AOR = 2.10, 95% CI = 1.50 – 2.93); ≥ daily heroin injection (AOR = 1.57, 95% CI = 1.08 – 2.26); ≥ daily crack smoking (AOR = 2.06, 95% CI = 1.44 – 2.95); being a victim of violence (AOR = 1.48, 95% CI = 1.04 – 2.12); and non-fatal overdose (AOR = 1.67, 95% CI = 1.67 (1.00 – 2.79) were independently and positively associated with methadone injection; female gender (AOR = 0.47, 95% CI = 0.30 – 0.75) was negatively associated. Discussion and Conclusion The diversion of methadone for illicit injection in this urban setting was associated with several markers of addiction severity and other health and social vulnerabilities. Scientific Significance These findings underscore the need to ensure methadone accessibility while limiting diversion-related risk.

Characteristics Associated with Nonmedical Methadone Use among People Who Inject Drugs in California

“…In our study, nonmedical methadone use was not associated with nonfatal overdose in the last 6 months. This finding has been reported in Oslo, Norway (Bretteville-Jensen et al, 2015) and contradicts a study in Vancouver, Canada that found such an association (Tucker et al, 2015). In the context of calls for rapid expansion of OAT (Perlman & Jordan, 2018;Saloner et al, 2018), this finding is important, as it supports that nonmedical methadone use, a sequela of OAT, may not lead to increased risk for overdose as is commonly thought.…”

“…Designing optimal OAT regimens requires an understanding of characteristics and behaviors of those who use nonmedical methadone. The vast majority of studies report the association between nonmedical methadone use, opioid dependence, and frequency of injection drug use (Genberg et al, 2013;Ompad et al, 2008;Reddon et al, 2018;Tucker et al, 2015). A Canadian study of people who inject drugs (PWID) identified characteristics associated with nonmedical methadone use that included homelessness, frequent heroin injection, frequent crack cocaine use, and, notably, nonfatal overdose (Tucker et al, 2015).…”

“…The vast majority of studies report the association between nonmedical methadone use, opioid dependence, and frequency of injection drug use (Genberg et al, 2013;Ompad et al, 2008;Reddon et al, 2018;Tucker et al, 2015). A Canadian study of people who inject drugs (PWID) identified characteristics associated with nonmedical methadone use that included homelessness, frequent heroin injection, frequent crack cocaine use, and, notably, nonfatal overdose (Tucker et al, 2015). Conversely, a Norwegian study found no association between nonmedical methadone use and nonfatal overdose (Bretteville-Jensen, Lillehagen, Gjersing, & Andreas, 2015).…”

Health harms of non‐medical prescription opioid use: A systematic review

“…Ultimately, 182 studies met the inclusion criteria; three studies only included event count and not participant sample size [13][14][15]. A total of 53 (29%) studies employed cross-sectional, population-based and nationally representative observational designs [7,14,; 13 (7%) employed longitudinal, cohort-based observational designs [64][65][66][67][68][69][70][71][72][73][74][75][76]; 4 (2%) employed case control designs [77][78][79][80]; 6 (3%)…”

Unintentional Opioid Overdoses Treated at University Clinic of Toxicology-Skopje in a Nine-Year-Period

“…However, the risk of sedation and respiratory depression with improper methadone dosing remains. Despite precautions for methadone prescription such as the dispensing of methadone under daily witnessed supervision in unstable patients and regular urine drug screen testing to verify compliance, fatalities associated with methadone have increased markedly across numerous jurisdictions in recent years (3).…”