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Elbasvir / grazoprevir Side Effects

For the Consumer

Applies to elbasvir / grazoprevir: oral tablet

In addition to its needed effects, some unwanted effects may be caused by elbasvir / grazoprevir. In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking elbasvir / grazoprevir:

Incidence not known:
  • Dark urine
  • fever with or without chills
  • light-colored stools
  • loss of appetite
  • nausea and vomiting
  • unusual tiredness
  • upper stomach pain
  • yellow eyes or skin

Minor Side Effects

Some of the side effects that can occur with elbasvir / grazoprevir may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Headache

For Healthcare Professionals

Applies to elbasvir / grazoprevir: oral tablet


In clinical trials, the safety of this drug (with or without ribavirin) was assessed in patients with chronic hepatitis C virus (HCV) infection with compensated liver disease (with or without cirrhosis). Clinical trials included therapy-naive and therapy-experienced (peginterferon alfa/ribavirin-experienced, peginterferon alfa/ribavirin/HCV protease inhibitor-experienced) patients, with and without HCV/HIV-coinfection; at least 1 clinical trial included patients with severe renal dysfunction, including those on hemodialysis.

The manufacturer product information for ribavirin should be consulted, if applicable.[Ref]


Common (1% to 10%): Rash/pruritus[Ref]


Very common (10% or more): Nausea (up to 11%)
Common (1% to 10%): Diarrhea, abdominal pain[Ref]


Common (1% to 10%): Anemia
Uncommon (0.1% to 1%): Decreased hemoglobin
Frequency not reported: CD4+ T-cell counts increased, CD4+ T-cell counts decreased[Ref]

The change from baseline in hemoglobin (Hgb) levels averaged about -2.2 g/dL in patients using this drug with ribavirin for 16 weeks and -0.3 g/dL in patients using this drug alone for 12 weeks. Hgb level decreased during the first 8 weeks of therapy, stayed low during the remainder of therapy, and normalized to baseline levels during follow-up. Less than 1% of patients using this drug with ribavirin had Hgb levels decrease to less than 8.5 g/dL during therapy; no patients using this drug alone had Hgb levels less than 8.5 g/dL.

In therapy-naive and therapy-experienced HCV/HIV-coinfected patients treated with this drug alone for 12 weeks, increase of CD4+ T-cell counts (of about 31 and 32 cells/mm3, respectively) was observed at the end of therapy. In therapy-experienced HCV/HIV-coinfected patients treated with this drug with ribavirin for 16 weeks, CD4+ T-cell counts decreased about 135 cells/mm3 by the end of therapy.[Ref]


During clinical trials with this drug (with or without ribavirin), regardless of duration of therapy, elevated bilirubin (greater than 2.5 x ULN) was reported in 6% and less than 1% of patients using this drug with ribavirin and alone, respectively. These increases were primarily indirect and generally associated with ribavirin coadministration. Elevated bilirubin was usually not associated with elevated serum ALT.

During clinical trials with this drug (with or without ribavirin), regardless of duration of therapy, ALT in 12 of 1599 patients increased from normal levels to greater than 5 times the upper limit of normal (5 x ULN), usually at or after 8 weeks of therapy (mean onset: 10 weeks; range: 6 to 12 weeks). These late ALT elevations were generally asymptomatic and most resolved with continued use or after completion of therapy. Late ALT elevations occurred more often in patients higher grazoprevir plasma levels (e.g., female, Asian, age at least 65 years). Incidence of late ALT elevations was not affected by duration of therapy and cirrhosis was not a risk factor.[Ref]

Common (1% to 10%): Elevated bilirubin
Uncommon (0.1% to 1%): Elevated ALT[Ref]


Common (1% to 10%): Arthralgia[Ref]

Nervous system

Very common (10% or more): Headache (up to 11%)[Ref]


Very common (10% or more): Fatigue (up to 11%)
Common (1% to 10%): Irritability[Ref]


Common (1% to 10%): Insomnia, depression[Ref]


Common (1% to 10%): Dyspnea[Ref]


1. "Product Information. Zepatier (elbasvir-grazoprevir)." Merck & Company Inc, Whitehouse Station, NJ.

Not all side effects for elbasvir / grazoprevir may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.