Cannabis use did not reduce hepatitis C cure rates in patients on opioid substitution therapy | Research

The takeaway

In a real-world registry of nearly 8,000 hepatitis C patients, cannabis use had no significant effect on cure rates (SVR) in either standard patients or those on opioid substitution therapy.

Hepatologists, infectious disease specialists, and addiction medicine physicians managing hepatitis C in substance-using populations.

Cannabis: no effect on cure rates

What the researchers found

Cannabis use did not significantly influence SVR rates in either intention-to-treat or per-protocol analysis, regardless of opioid substitution therapy status. High alcohol consumption slightly reduced ITT cure rates (due to more lost-to-follow-up), but per-protocol rates were similar. OST patients had higher LTFU rates but similar per-protocol cure rates.

Why it matters

Concerns about cannabis and alcohol use in hepatitis C patients on opioid substitution have led some clinicians to defer or deny treatment. This study shows these concerns are unfounded for cure rates.

The numbers in context

739 OST patients, 7,008 non-OST. Non-OST/no drug use SVR: 91-92% (ITT). OST SVR: 83-86% (ITT). Difference mainly due to LTFU (11-12% vs 2-3%). Cannabis use: no significant effect on SVR in any analysis.

How the study worked

Analysis of the German Hepatitis C Registry (DHC-R), a national multicenter prospective real-world registry. 739 OST patients and 7,008 non-OST patients treated with direct-acting antivirals.

What this study cannot tell us

Self-reported substance use may be underestimated. Cannabis type and quantity not specified. LTFU after end of treatment could mask some treatment failures. German healthcare context may not generalize to all settings.

How to read the evidence

Rated strong because this is a large national registry with nearly 8,000 patients and prospective data collection.

When this study was published

Published in 2019.

The bigger picture

This large registry study removes a barrier to treating hepatitis C in substance-using populations. If cannabis and alcohol do not reduce cure rates, there is no pharmacological reason to withhold treatment from these patients.

Questions still open

Should substance use screening be used to guide HCV treatment decisions? Does cannabis affect treatment adherence even if it does not affect cure rates? Would similar results be seen with other drug classes?

Common questions

Does cannabis use affect hepatitis C treatment?

No. In this large German registry, cannabis use had no significant effect on cure rates for hepatitis C, whether patients were on opioid substitution therapy or not.

Should substance users be treated for hepatitis C?

This study supports treating substance-using patients. Cure rates were similar when controlling for treatment completion, and neither cannabis nor moderate alcohol use reduced effectiveness.

Read the original research

Alcohol and Cannabis Consumption Does Not Diminish Cure Rates in a Real-World Cohort of Chronic Hepatitis C Virus Infected Patients on Opioid Substitution Therapy-Data From the German Hepatitis C-Registry (DHC-R).

Substance abuse : research and treatment, 13, 1178221819835847

View on PubMed ↗Publisher’s paper ↗

Citation

Christensen, Stefan; Buggisch, Peter; Mauss, Stefan; Böker, Klaus Hw; Müller, Tobias; Klinker, Hartwig; Zimmermann, Tim; Serfert, Yvonne; Weber, Bernd; Reimer, Jens; Wedemeyer, Heiner. (2019). Alcohol and Cannabis Consumption Does Not Diminish Cure Rates in a Real-World Cohort of Chronic Hepatitis C Virus Infected Patients on Opioid Substitution Therapy-Data From the German Hepatitis C-Registry (DHC-R).. Substance abuse : research and treatment, 13, 1178221819835847. https://doi.org/10.1177/1178221819835847