ELBASVIR Drug Interactions: What You Need to Know

INTERACTIONS Co-administration of ZEPATIER with moderate CYP3A inducers is not recommended as they may decrease the plasma concentration of ZEPATIER. ( 7 ) Co-administration of ZEPATIER with certain strong CYP3A inhibitors is not recommended as they may increase the plasma concentration of ZEPATIER. ( 7 ) Clearance of HCV infection with direct-acting antivirals may lead to changes in hepatic function, which may impact safe and effective use of concomitant medications. Frequent monitoring of relevant laboratory parameters (INR or blood glucose) and dose adjustments of certain concomitant medications may be necessary. ( 7.2 ) Consult the full prescribing information prior to and during treatment for potential drug interactions. ( 4 , 5.5 , 7 , 12.3 )

7.1 Potential for Drug Interactions Grazoprevir is a substrate of OATP1B1/3 transporters. Co-administration of ZEPATIER with OATP1B1/3 inhibitors that are known or expected to significantly increase grazoprevir plasma concentrations is contraindicated <span class="opacity-50 text-xs">[see Contraindications (4) , Clinical Pharmacology (12.3) , and Table 2 ]</span> . Elbasvir and grazoprevir are substrates of CYP3A and P-gp, but the role of intestinal P-gp in the absorption of elbasvir and grazoprevir appears to be minimal. Co-administration of moderate or strong inducers of CYP3A with ZEPATIER may decrease elbasvir and grazoprevir plasma concentrations, leading to reduced therapeutic effect of ZEPATIER. Co-administration of ZEPATIER with strong CYP3A inducers or efavirenz is contraindicated <span class="opacity-50 text-xs">[see Contraindications (4) , Clinical Pharmacology (12.3) , and Table 2 ]</span>. Co-administration of ZEPATIER with moderate CYP3A inducers is not recommended <span class="opacity-50 text-xs">[see Warnings and Precautions (5.5) , Clinical Pharmacology (12.3) , and Table 6 ]</span>. Co-administration of ZEPATIER with strong CYP3A inhibitors may increase elbasvir and grazoprevir concentrations. Co-administration of ZEPATIER with certain strong CYP3A inhibitors is not recommended <span class="opacity-50 text-xs">[see Warnings and Precautions (5.5) , Clinical Pharmacology (12.3) , and Table 6 ]</span> .

7.2 Established and other Potentially Significant Drug Interactions If dose adjustments of concomitant medications are made due to treatment with ZEPATIER, doses should be readjusted after administration of ZEPATIER is completed. Clearance of HCV infection with direct-acting antivirals may lead to changes in hepatic function, which may impact the safe and effective use of concomitant medications. For example, altered blood glucose control resulting in serious symptomatic hypoglycemia has been reported in diabetic patients in postmarketing case reports and published epidemiological studies. Management of hypoglycemia in these cases required either discontinuation or dose modification of concomitant medications used for diabetes treatment. Frequent monitoring of relevant laboratory parameters (e.g., International Normalized Ratio [INR] in patients taking warfarin, blood glucose levels in diabetic patients) or drug concentrations of concomitant medications such as CYP450 substrates with a narrow therapeutic index (e.g., certain immunosuppressants) is recommended to ensure safe and effective use. Dose adjustments of concomitant medications may be necessary.

Table

6 provides a listing of established or potentially clinically significant drug interactions. The drug interactions described are based on studies conducted with either ZEPATIER, the components of ZEPATIER (elbasvir [EBR] and grazoprevir [GZR]) as individual agents, or are predicted drug interactions that may occur with ZEPATIER [see Contraindications (4) , Warnings and Precautions (5.5) , and Clinical Pharmacology (12.3) ] .

Table

6: Potentially Significant Drug Interactions: Alteration in Dose May Be Recommended Based on Results from Drug Interaction Studies or Predicted Interactions This table is not all inclusive.

Concomitant Drug

Class: Drug Name Effect on Concentration ↓ = decrease, ↑ = increase Clinical Comment Antibiotics : Nafcillin ↓ EBR ↓ GZR Co-administration of ZEPATIER with nafcillin may lead to reduced therapeutic effect of ZEPATIER. Co-administration is not recommended. Antifungals: oral Ketoconazole These interactions have been studied in healthy adults. ↑ EBR ↑ GZR Co-administration of oral ketoconazole is not recommended.

Endothelin

Antagonists: Bosentan ↓ EBR ↓ GZR Co-administration of ZEPATIER with bosentan may lead to reduced therapeutic effect of ZEPATIER. Co-administration is not recommended. Immunosuppressants: Tacrolimus ↑ tacrolimus Frequent monitoring of tacrolimus whole blood concentrations, changes in renal function, and tacrolimus-associated adverse events upon the initiation of co-administration is recommended.

Hiv

Medications: Etravirine ↓ EBR ↓ GZR Co-administration of ZEPATIER with etravirine may lead to reduced therapeutic effect of ZEPATIER. Co-administration is not recommended. Elvitegravir/ cobicistat/ emtricitabine/ tenofovir (disoproxil fumarate or alafenamide) ↑ EBR ↑ GZR Co-administration of cobicistat-containing regimens is not recommended. HMG-CoA Reductase Inhibitors See Drug Interactions (7.3) for a list of HMG Co-A reductase inhibitors without clinically relevant interactions with ZEPATIER. : Atorvastatin ↑ atorvastatin The dose of atorvastatin should not exceed a daily dose of 20 mg when co-administered with ZEPATIER. Rosuvastatin ↑ rosuvastatin The dose of rosuvastatin should not exceed a daily dose of 10 mg when co-administered with ZEPATIER.

Fluvastatin Lovastatin

Simvastatin ↑ fluvastatin ↑ lovastatin ↑ simvastatin Statin-associated adverse events such as myopathy should be closely monitored. The lowest necessary dose should be used when co-administered with ZEPATIER. Wakefulness-Promoting Agents: Modafinil ↓ EBR ↓ GZR Co-administration of ZEPATIER with modafinil may lead to reduced therapeutic effect of ZEPATIER. Co-administration is not recommended.

7.3 Drugs without Clinically Significant Interactions with ZEPATIER The interaction between the components of ZEPATIER (elbasvir or grazoprevir) or ZEPATIER and the following drugs were evaluated in clinical studies, and no dose adjustments are needed when ZEPATIER is used with the following drugs individually: acid reducing agents (proton pump inhibitors, H2 blockers, antacids), buprenorphine/naloxone, digoxin, dolutegravir, methadone, mycophenolate mofetil, oral contraceptive pills, phosphate binders, pitavastatin, pravastatin, prednisone, raltegravir, ribavirin, rilpivirine, tenofovir disoproxil fumarate, and sofosbuvir <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span> . No clinically relevant drug-drug interaction is expected when ZEPATIER is co-administered with abacavir, emtricitabine, entecavir, and lamivudine.

ZEPATIER is contraindicated in patients with moderate or severe hepatic impairment (Child-Pugh B or C) due to the expected significantly increased grazoprevir plasma concentration and the increased risk of alanine aminotransferase (ALT) elevations [see Warnings and Precautions (5.2) , Use in Specific Populations (8.9) , and Clinical Pharmacology (12.3) ] . ZEPATIER is contraindicated in patients with moderate or severe hepatic impairment (Child-Pugh B or C) or those with any history of hepatic decompensation due to the risk of hepatic decompensation [see Warnings and Precautions (5.3) , Use in Specific Populations (8.9) ] . ZEPATIER is contraindicated with inhibitors of organic anion transporting polypeptides 1B1/3 (OATP1B1/3) that are known or expected to significantly increase grazoprevir plasma concentrations, strong inducers of cytochrome P450 3A (CYP3A), and efavirenz [see Warnings and Precautions (5.5) , Drug Interactions (7) , and Clinical Pharmacology (12.3) ] . If ZEPATIER is administered with ribavirin, the contraindications to ribavirin also apply to this combination regimen. Refer to the ribavirin prescribing information for a list of contraindications for ribavirin.

Table

2 lists drugs that are contraindicated with ZEPATIER.

Table

2: Drugs that are Contraindicated with ZEPATIER Drug Class Drug(s) within Class that are Contraindicated Clinical Comment This table is not a comprehensive list of all drugs that strongly induce CYP3A. This table may not include all OATP1B1/3 inhibitors that significantly increase grazoprevir plasma concentrations.

Anticonvulsants Phenytoin Carbamazepine

May lead to loss of virologic response to ZEPATIER due to significant decreases in elbasvir and grazoprevir plasma concentrations caused by strong CYP3A induction.

Antimycobacterials Rifampin

May lead to loss of virologic response to ZEPATIER due to significant decreases in elbasvir and grazoprevir plasma concentrations caused by strong CYP3A induction.

Herbal

Products St. John's Wort (Hypericum perforatum) May lead to loss of virologic response to ZEPATIER due to significant decreases in elbasvir and grazoprevir plasma concentrations caused by strong CYP3A induction.

Hiv

Medications Efavirenz Efavirenz is included as a strong CYP3A inducer in this table, since co-administration reduced grazoprevir exposure by ≥80% [see Table 9 ] . May lead to loss of virologic response to ZEPATIER due to significant decreases in elbasvir and grazoprevir plasma concentrations caused by CYP3A induction.

Hiv

Medications Atazanavir Darunavir Lopinavir Saquinavir Tipranavir May increase the risk of ALT elevations due to a significant increase in grazoprevir plasma concentrations caused by OATP1B1/3 inhibition.

Immunosuppressants Cyclosporine

May increase the risk of ALT elevations due to a significant increase in grazoprevir plasma concentrations caused by OATP1B1/3 inhibition. Patients with moderate or severe hepatic impairment (Child-Pugh B or C). ( 4 ) OATP1B1/3 inhibitors that are known or expected to significantly increase grazoprevir plasma concentrations, strong CYP3A inducers, and efavirenz. ( 4 ) If ZEPATIER is administered with ribavirin, the contraindications to ribavirin also apply. ( 4 )

AND PRECAUTIONS Risk of Hepatitis B Virus Reactivation: Test all patients for evidence of current or prior HBV infection before initiation of HCV treatment. Monitor HCV/HBV coinfected patients for HBV reactivation and hepatitis flare during HCV treatment and post-treatment follow-up. Initiate appropriate patient management for HBV infection as clinically indicated. ( 5.1 )

Alt

Elevations: Perform hepatic laboratory testing prior to therapy, at treatment week 8, and as clinically indicated. For patients receiving 16 weeks of therapy, perform additional hepatic laboratory testing at treatment week 12. For ALT elevations on ZEPATIER, follow recommendations in full prescribing information. ( 5.2 ) Risk of Hepatic Decompensation/Failure in Patients with Evidence of Advanced Liver Disease: Hepatic decompensation/failure, including fatal outcomes, have been reported mostly in patients with cirrhosis and baseline moderate or severe liver impairment (Child-Pugh B or C) treated with HCV NS3/4A protease inhibitor-containing regimens. Monitor for clinical and laboratory evidence of hepatic decompensation. Discontinue ZEPATIER in patients who develop evidence of hepatic decompensation/failure. ( 5.3 )

Risk

Associated with Ribavirin Combination Treatment: If ZEPATIER is administered with ribavirin, the warnings and precautions for ribavirin also apply. ( 5.4 )

5.1 Risk of Hepatitis B Virus Reactivation in Patients Coinfected with HCV and HBV Hepatitis B virus (HBV) reactivation has been reported in HCV/HBV coinfected patients who were undergoing or had completed treatment with HCV direct acting antivirals, and who were not receiving HBV antiviral therapy. Some cases have resulted in fulminant hepatitis, hepatic failure and death. Cases have been reported in patients who are HBsAg positive and also in patients with serologic evidence of resolved HBV infection (i.e., HBsAg negative and anti-HBc positive). HBV reactivation has also been reported in patients receiving certain immunosuppressant or chemotherapeutic agents; the risk of HBV reactivation associated with treatment with HCV direct-acting antivirals may be increased in these patients. HBV reactivation is characterized as an abrupt increase in HBV replication manifesting as a rapid increase in serum HBV DNA level. In patients with resolved HBV infection reappearance of HBsAg can occur. Reactivation of HBV replication may be accompanied by hepatitis, i.e., increases in aminotransferase levels and, in severe cases, increases in bilirubin levels, liver failure, and death can occur. Test all patients for evidence of current or prior HBV infection by measuring HBsAg and anti-HBc before initiating HCV treatment with ZEPATIER. In patients with serologic evidence of HBV infection, monitor for clinical and laboratory signs of hepatitis flare or HBV reactivation during HCV treatment with ZEPATIER and during post-treatment follow-up. Initiate appropriate patient management for HBV infection as clinically indicated.

5.2 Increased Risk of ALT Elevations During clinical trials with ZEPATIER with or without ribavirin, 1% of subjects experienced elevations of ALT from normal levels to greater than 5 times the upper limit of normal (ULN), generally at or after treatment week 8. ALT elevations were typically asymptomatic and most resolved with ongoing or completion of therapy. Higher rates of late ALT elevations occurred in the following subpopulations: female sex (2% [10/608]), Asian race (2% [4/164]), and age 65 years or older (2% [3/177]) <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) ]</span> . Hepatic laboratory testing should be performed prior to therapy, at treatment week 8, and as clinically indicated. For patients receiving 16 weeks of therapy, additional hepatic laboratory testing should be performed at treatment week 12. Patients should be instructed to consult their healthcare professional without delay if they have onset of fatigue, weakness, lack of appetite, nausea and vomiting, jaundice, or discolored feces. Consider discontinuing ZEPATIER if ALT levels remain persistently greater than 10 times the ULN. Discontinue ZEPATIER if ALT elevation is accompanied by signs or symptoms of liver inflammation or increasing conjugated bilirubin, alkaline phosphatase, or International Normalized Ratio (INR).

5.3 Risk of Hepatic Decompensation/Failure in Patients with Evidence of Advanced Liver Disease Postmarketing cases of hepatic decompensation/failure, including those with fatal outcomes, have been reported in patients treated with HCV NS3/4A protease inhibitor-containing regimens, including ZEPATIER. Reported cases occurred in patients treated with HCV NS3/4A protease inhibitor-containing regimens with baseline cirrhosis with and without moderate or severe liver impairment (Child-Pugh B or C) as well as some patients without cirrhosis. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Hepatic laboratory testing should be performed in all patients <span class="opacity-50 text-xs">[see Warnings and Precautions (5.2) ]</span>. In patients with compensated cirrhosis (Child-Pugh A) or evidence of advanced liver disease, such as portal hypertension, more frequent hepatic laboratory testing may be warranted; and patients should be monitored for signs and symptoms of hepatic decompensation such as the presence of jaundice, ascites, hepatic encephalopathy, and variceal hemorrhage. Discontinue ZEPATIER in patients who develop evidence of hepatic decompensation/failure. ZEPATIER is contraindicated in patients with moderate to severe hepatic impairment (Child-Pugh B or C) or those with any history of prior hepatic decompensation <span class="opacity-50 text-xs">[see Contraindications (4) , Adverse Reactions (6.1) , Use in Specific Populations (8.9) , and Clinical Pharmacology (12.3) ]</span> .

5.4 Risks Associated with Ribavirin Combination Treatment If ZEPATIER is administered with ribavirin, the warnings and precautions for ribavirin, including the pregnancy avoidance warning, also apply to this combination regimen. Refer to the ribavirin prescribing information for a full list of warnings and precautions for ribavirin <span class="opacity-50 text-xs">[see Dosage and Administration (2.2) ]</span> .

5.5 Risk of Adverse Reactions or Reduced Therapeutic Effect Due to Drug Interactions The concomitant use of ZEPATIER and certain drugs may result in known or potentially significant drug interactions, some of which may lead to: Possible clinically significant adverse reactions from greater exposure of concomitant drugs or components of ZEPATIER. Significant decrease of elbasvir and grazoprevir plasma concentrations which may lead to reduced therapeutic effect of ZEPATIER and possible development of resistance.

See Tables

2 and 6 for steps to prevent or manage these known or potentially significant drug interactions, including dosing recommendations [see Contraindications (4) and Drug Interactions (7.2) ] .