What additional tests and treatment are recommended for a patient with a positive hepatitis C test who is currently on buprenorphine (opioid partial agonist) for opioid use disorder?

Management of Hepatitis C in a Patient on Buprenorphine Treatment

For a patient with a positive hepatitis C test who is stable on buprenorphine for opioid use disorder, HCV RNA testing should be performed immediately to confirm active infection, followed by genotyping and fibrosis assessment to guide treatment decisions. 1, 2

Diagnostic Testing Algorithm

Confirmation of Active HCV Infection

• Perform HCV RNA testing to confirm active infection, as a positive antibody test alone does not distinguish between current and resolved infection 1, 3
• If HCV RNA is positive, this confirms current active infection requiring further evaluation 3
• If HCV RNA is negative, consider supplemental antibody testing to distinguish between resolved infection and false-positive antibody result 1, 3

Additional Required Testing

• Quantitative HCV RNA and genotype/subtype determination to guide treatment selection 1, 2
• Liver function tests (ALT, AST, alkaline phosphatase, bilirubin, albumin, INR) to assess liver damage 2
• Complete blood count to evaluate for cytopenias associated with advanced liver disease 2
• Assessment of liver fibrosis severity using:
  • Non-invasive tests such as:
    • FIB-4 score (age × AST/[platelet count × √ALT]) 1
    • APRI (AST-to-platelet ratio index) 1
    • Transient elastography (FibroScan) if available 1
  • Liver biopsy may be considered if non-invasive tests are inconclusive 1
• Abdominal ultrasound to screen for hepatocellular carcinoma and evaluate for cirrhosis 1
• HIV testing due to common risk factors and impact on treatment approach 2
• Hepatitis B surface antigen testing to rule out co-infection 1

Treatment Approach

Assessment for Treatment Eligibility

• Evaluate for simplified versus standard treatment pathway:
  • Simplified treatment eligible if: compensated cirrhosis (Child-Pugh A) with no prior HCV treatment 1
  • Standard treatment pathway needed if: decompensated cirrhosis, prior HCV treatment, end-stage renal disease, HIV or HBV co-infection, pregnancy, or hepatocellular carcinoma 1

Treatment Regimen

• Direct-acting antiviral (DAA) therapy is the standard of care, with regimen selection based on:
  • HCV genotype and subtype 1
  • Presence/absence of cirrhosis 1
  • Prior treatment history 1
  • Comorbidities 1

Medication Considerations with Buprenorphine

• Buprenorphine can be safely continued during HCV treatment 4
• No clinically significant drug interactions have been observed between buprenorphine/naloxone and current DAA regimens such as sofosbuvir/velpatasvir 4
• Monitor liver function tests during treatment, as rare cases of hepatotoxicity with buprenorphine have been reported, particularly in HCV-infected patients 5, 6

Monitoring During and After Treatment

• HCV RNA testing at week 4 of treatment, end of treatment, and 12 weeks post-treatment to confirm sustained virological response (SVR) 2
• Regular monitoring of liver function tests during treatment 2
• For patients with cirrhosis, continue hepatocellular carcinoma surveillance with ultrasound every 6 months even after achieving SVR 1

Important Considerations and Pitfalls

Buprenorphine-Specific Considerations

• Buprenorphine should be continued during HCV treatment as discontinuation could lead to relapse of opioid use 7
• While rare cases of hepatotoxicity with buprenorphine have been reported in HCV-infected patients, the benefits of continuing buprenorphine for opioid use disorder typically outweigh the risks 5, 6
• Successful treatment of HCV in patients on buprenorphine requires integrated care addressing both opioid use disorder and HCV infection 7

Patient Education

• Advise the patient to avoid alcohol to prevent further liver damage 1
• Counsel on preventing HCV transmission to others:
  • Avoid sharing needles, syringes, or other drug preparation equipment 1
  • Do not share personal items that might have blood on them (razors, toothbrushes) 1
  • Cover any bleeding wounds 1
  • Do not donate blood, organs, or semen 1
• Discuss that HCV treatment success rates are high (>95%) with current DAA regimens, even in patients on buprenorphine 1

Follow-up

• After achieving SVR, patients with ongoing risk factors (such as injection drug use) should be tested annually for HCV RNA to detect potential reinfection 1
• Continue to support the patient's recovery from opioid use disorder through maintenance of buprenorphine therapy and appropriate psychosocial support 7