Drug-Drug Interactions of Grazoprevir/Elbasvir in Taiwan


Co-morbid diseases often present in a substantial proportion of patients with chronic hepatitis C (CHC) and require drugs to treat and control. Grazoprevir/elbavir is metabolized by cytochrome P-450 enzyme of liver. Drug-drug interactions (DDIs) are important issue before commencing direct acting antiviral agents (DAA) treatment for CHC patients. Few studies from Western countries reported that the percentages of DDIs of grazoprevir/elbasvir are limited.In Asia, real-world analysis of DDIs of grazoprevir/elbasvir is lacking and needs to be clarified.

Full Title of Study: “The Real World Analysis of Drug-Drug Interactions of Grazoprevir/Elbasvir in Treatment of Chronic Hepatitis C Patients in Taiwan”

Study Type

  • Study Type: Observational
  • Study Design
    • Time Perspective: Retrospective
  • Study Primary Completion Date: February 25, 2019

Detailed Description

This is a multi-center, retrospective study. Five hospitals in Taiwan and 400 patients Patients treated with grazoprevir/elbasvir during August 2017 to July 2018 are candidates of study subjects. All the required study information will be recorded with detailed chart review. DDI will be evaluated by HEP Drug Interactions (www.hep-druginteractions.org) assessment of comidications: Category 0: Classification not possible due to lack of information; Category 1: No clinical interaction possible; Category 2: May require dose adjustment/closer monitoring; Category 3: Coadministration not recommended or contraindicated. The assessment of DDI will be evaluated and recorded according to the suggested categories, the number of patients at risk for a clinically relevant DDI, and the ratio of patients with at least one predicted DDI between medication of grazoprevir/elbasvir will be calculated.


  • Drug: elbasvir/grazoprevir
    • Comedications during elbasvir/grazoprevir will be recorded and analyzed for potential drug-drug interaction.

Arms, Groups and Cohorts

  • Drug interaction of Elbasvir/Grazoprevir
    • Patients treated with elbasvir/grazoprevir will be enrolled. DDI will be evaluated.

Clinical Trial Outcome Measures

Primary Measures

  • the potential drug drug interaction of elbasvir/grazoprevor
    • Time Frame: DDI will be assessed before and through the 12 weeks or 16 weeks of elbasvir/grazoprevir treatment
    • the ratio of patients with at least one predicted DDI will be analyzed.

Secondary Measures

  • the comorbid diseases of CHC patients in Taiwan
    • Time Frame: Comorbid diseases will be assessed before elbasvir/grazoprevir treatment.
    • Comorbid diseases will be recorded and categorized by involved organ systems before elbasvir/grazoprevir treatment.

Participating in This Clinical Trial

Inclusion Criteria

  • Patients treated with grazoprevir/elbasvir are candidates of study subjects. Exclusion Criteria:

  • none

Gender Eligibility: All

Minimum Age: 20 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • National Cheng-Kung University Hospital
  • Collaborator
    • Merck Sharp & Dohme Corp.
  • Provider of Information About this Clinical Study
    • Principal Investigator: Pin-Nan Cheng, Associate Professor – National Cheng-Kung University Hospital
  • Overall Official(s)
    • Pin-Nan Cheng, M.D., Principal Investigator, National Cheng-Kung University Hospital

Clinical trials entries are delivered from the US National Institutes of Health and are not reviewed separately by this site. Please see the identifier information above for retrieving further details from the government database.

At TrialBulletin.com, we keep tabs on over 200,000 clinical trials in the US and abroad, using medical data supplied directly by the US National Institutes of Health. Please see the About and Contact page for details.