Pay attention when STARTING medications in patients taking hepatitis C antivirals

Delay any interacting medications that aren't critical, since hepatitis C treatment is usually just for 8 to 12 weeks....
Abdelwahab Ward, BS Pharm, PharmD
2 minute read

As a pharmacist, you'll face MANY potential drug interactions with hepatitis C antivirals (Epclusa [Qurevo], Mavyret, etc) even if you didn't start these medications. Interactions can lead to toxicity or treatment failure. And this can be an expensive mistake. Plus, hepatitis C medications may fly under the radar if the physician didn't prescribe them. Update the EHR with ALL medications (Rxs, OTCs, supplements, etc).

NPS-adv

Delay any interacting medications that aren't critical, since hepatitis C treatment is usually just for 8 to 12 weeks. Keep in mind, interactions vary based on the hepatitis C antiviral, but a few should raise red flags.

Examples on drug interactions with hepatitis c antivirals
  • Acid reducers can decrease antiviral absorption. Be aware of dosing limits and spacing with PPIs, H2-blockers, and antacids. For example, usually avoid a PPI with Epclusa. Use an H2-blocker instead, dosed at the same time as Epclusa or 12 hours apart.
  • Statin side effects (myopathy, etc) may be more common since antivirals can increase statin levels. Generally, reduce or hold the statin with hepatitis C medications. For instance, limit rosuvastatin to 10 mg/day with Mavyret or Zepatier. Restart the original statin dose after stopping the antiviral.
  • Anticonvulsants can reduce antiviral levels. Avoid potent CYP3A4 inducers, such as phenytoin or carbamazepine, in combo with any hepatitis C antiviral. Think of valproic acid (Depakine) or lamotrigine (Lamictal) as an option.
  • Supplements should usually be avoided. For example, St. John's wort is a CYP450 inducer and lowers antiviral levels.

NPS-adv

Evaluate drug interactions identified by the EHR or use the Univ of Liverpool's website at https://www.hep-druginteractions.org/. It's recognized as an authority by the Infectious Diseases Society of America.

References

  1. Recommendations for Testing, Managing, and Treating Hepatitis C - HCV Guidance. [online] Available at: https://www.hcvguidelines.org.
  2. Marks K, Naggie S. Management of Hepatitis C in 2019. JAMA. 2019 May 17. Available at: https://pubmed.ncbi.nlm.nih.gov/31099822.

This note has been edited and reviewed by the pharmacy doctors on NPS team.

  • Published on March 08, 2021
  • This note last updated in March 13, 2025
Abdelwahab Ward, BS Pharm, PharmD