Hydromorphone Controlled-Release Dispensing Rates May Predict HCV Incidence

Compared with all opioid prescriptions, a higher hydromorphone controlled-release dispensing rate was a strong predictor of hepatitis C virus (HCV) incidence, according to a study published in the Journal of Viral Hepatitis.¹

One result of the rising prevalence of injection-drug use and the opioid epidemic may be increases in acute HCV incidence. Among persons who inject drugs, the sharing of injection drug preparation equipment had been linked to a greater percentage of incident HCV cases than sharing needles/syringes.

Hydromorphone controlled-release has been associated with frequent reuse and sharing of injection drug preparation equipment in Canada and Europe. This is likely the result of the insolubility of controlled release hydromorphone, which results in a significant amount of residue in the injection drug preparation equipment. This drug residual is often kept for reuse. Furthermore, drug excipients within hydromorphone controlled-release have been shown to preserve virus survival in injection drug preparation equipment.

Therefore, this study clarified the relationship between hydromorphone controlled-release dispensing and HCV incidence by Health Unit region in Ontario, Canada.

The methods of this study were modeled after those reported by Van Handel et al² wherein county-level risk for HIV/HCV in the United States was assessed. However, Meyer and colleagues² used Health Unit region for analyses, because this is the geographic level at which HCV infections are tracked in Ontario. Since population-level incidence data for acute HCV was not available, new serologic diagnoses was used. Variables explored included drug-overdose mortality, prescription opioid sales, vehicle availability, lack of education, income, population density, poverty, White race/ethnicity, unemployment, opioid substitution therapy, urban/rural status, and access to interstate.

Results supported previous evidence that local rates of total opioid prescriptions are related to the rate of new diagnoses of hepatitis C. There were 4079 new diagnoses of HCV infection reported across Ontario in 2016. The rate of infection by Health Unit region ranged from 13 to 138 per 100,000 population; prescriptions for hydromorphone controlled-release ranged from 0.3 to 3.7 kg per 10,000 residents. All variables analyzed were found to be independently associated with HCV infection rate at P <.05, with all but 1 variable below P =.0001.

Results showed that in Ontario more opioid prescriptions, lower income, white race, and greater opioid substitution therapy were associated with new diagnoses of hepatitis C. Further, a high hydromorphone controlled-release dispending rate was a stronger predictor of HCV incidence than all opioid prescriptions was (P <.0001 vs P =.02). When hydromorphone controlled-release was excluded from the opioid prescription variable, dispensing patterns of all other opioids was no longer significant (P =.34). This relationship between HCV incidence and hydromorphone controlled-release dispensing suggests that the type of opioid prescribed locally may contribute to HCV incidence variations.

Limitations of this study included the lack of data for incidence of acute hepatitis C and that the adjustment to more restrictive reporting guidelines for hepatitis C by Ontario Public Health in 2017 was not included in this study; the study authors hope to analyze this more restrictive data when new opioid prescribing data is available.

Although opioid agonist therapy has been shown to reduce the risk for HCV infection in people who use illicit drugs, this study showed that overall methadone use in the community was associated with a higher incidence of HCV. Similarly, results suggested that hydromorphone controlled-release dispending (but not all other opioids) was related to HCV incidence even when methadone use and other community variables associated with opioid use were controlled. Overall, the study authors concluded that, “These data add support to evidence that hydromorphone controlled-release use is contributing to HCV spread in Ontario.”

References

1. Meyer M, Bondy L, Koivu S, Koval J, Scarffe AD, Silverman MS. New hepatitis C diagnoses in Ontario, Canada are associated with local prescription patterns of a controlled release opioid [published online March 18, 2020]. J Viral Hepatitis. doi:10.1111/JVH.13292

2. Van Handel MM, Rose CE, Hallisey EJ, et al. County-level vulnerability assessment for rapid dissemination of HIV or HCV infections among persons who inject drugs, United States [published online November 1, 2016]. JAIDS. doi:10.1097/qau.0000000000001098