For individuals with a long-term opioid prescription for noncancer pain, risk for hepatitis C virus (HCV) acquisition was increased, suggesting that initiation of intravenous drug use may be correlated. These findings were published in JAMA Network Open.
Data were sourced from the British Columbia Centre for Disease Control Public Health Laboratory which included linked information about medical visits, hospitalizations, emergency department visits, cancers, pharmacy dispensation, and HCV laboratory testing between 1985-2017.
Individuals (N=382,478) who were tested for HCV ≥2 times, receiving their first negative result between 2000 and 2015 and who had no history of substance use, opioid agonist therapy, or prior HIV infection were assessed for HCV infection acquisition and prescription use of opioids.
Acute opioid use was defined as <90 episode days, long-term use as ≥90 episode days, long-term episodic use as <90 days of drug supply and/or <50% episode intensity, and long-term chronic use as ≥90 days of drug supply and/or ≥50% episode intensity.
The study population was 58.7% women, and they were aged mean 35.6 (standard deviation [SD], 12.3) years. During a median follow-up of 4.3 (interquartile range [IQR], 1.9-8.3) years, individuals received 2 (IQR, 2-3) HCV tests.
At baseline, most had been opioid-naïve (97.0%) and 2.0% were episodic and 1.0% chronic users. A total of 30,166 individuals initiated long-term opioid use during follow-up, of whom, 89.4% were episodic and 10.6% chronic users.
The median use of opioids lasted 228 days with a median drug supply of 40 days with morphine equivalents (MEQ) of 22.5. Stratified by long-term episodic and chronic use, chronic use associated with longer episodes (median, 1,968 vs 191 days), more drug supply (median, 1,389 vs 28 days), and higher doses (median, 35.1 vs 21.2 MEQ).
HCV seroconversion occurred among 1,947, equating to an incidence rate of 0.9 per 1000 person-years (py). Among the HCV cohort, 74.8% had evidence they had transitioned to using injectable drugs compared with 6.5% among the cohort who had not seroconverted to HCV.
The rate of HCV seroconversion was higher among patients with long-term opioid exposure (2.1 per 1,000 py) compared with those who had no long-term exposure (0.8 per 1,000 py).
Risk for HCV seroconversion was associated with long-term average daily dose ≥90 MEQ (adjusted hazard ratio [aHR], 5.1; 95% CI, 3.7-7.1), long-term chronic use (aHR, 4.7; 95% CI, 3.9-5.8), long-term average daily dose <90 MEQ (aHR, 3.1; 95% CI, 2.8-3.5), and long-term episodic use (aHR, 2.9; 95% CI, 2.6-3.3).
This study may have been biased by the assumption that HCV was acquired through injectable drug use. Other possible routes of infection included tattooing, sexual contact, and sharing of pipes used for smoking illicit drugs.
The study authors concluded that individuals with long-term opioid dispensation for noncancer pain increased risk for HCV seroconversion and may indicate a correlation between long-term opioid use and initiation of injecting drugs.
Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.
Wilton J, Wong S, Purssell R, et al. Association between prescription opioid therapy for noncancer pain and hepatitis c virus seroconversion.JAMA Netw Open. 2022;5(1):e2143050. doi:10.1001/jamanetworkopen.2021.43050
This article originally appeared on Clinical Pain Advisor