elbasvir + grazoprevir: clinical use

Prescribing considerations

• Initiate and monitor through a clinician experienced in chronic hepatitis C management.
• Confirm HCV genotype and assess viral factors, previous direct-acting antiviral exposure, cirrhosis and co-medication.
• Efficacy has not been demonstrated for genotypes 2, 3, 5 or 6 or retreatment after exposure to the same antiviral classes.
• Safety and efficacy have not been established in liver-transplant recipients.
• Review lactose intolerance and sodium intake where relevant.

Contraindications and cautions

• Hypersensitivity to either active ingredient or an excipient.
• Moderate or severe hepatic impairment: Child–Pugh B or C.
• Concomitant OATP1B inhibitors, including specified HIV protease inhibitors, cobicistat, ciclosporin and rifampicin.
• Concomitant CYP3A or P-glycoprotein inducers, including carbamazepine, phenytoin, efavirenz, etravirine, bosentan, modafinil and St John’s wort.

Monitoring

• Test hepatic function before and during treatment and when clinically indicated; investigate symptoms of hepatic inflammation promptly.
• Screen for current or previous hepatitis B and monitor coinfected patients for reactivation.
• Assess virological response using HCV RNA testing.
• Monitor glucose closely in people with diabetes and coordinate changes to glucose-lowering therapy.
• Increase INR surveillance for vitamin K antagonists and monitor medicines such as tacrolimus.

Clinical pharmacology

Elbasvir inhibits HCV NS5A; grazoprevir inhibits HCV NS3/4A protease. Both are CYP3A and P-glycoprotein substrates, and grazoprevir is also an OATP1B substrate. Elimination is predominantly faecal, with minimal renal excretion.

Formulation and product differences

• Fixed-combination, beige oval film-coated tablet.
• Contains lactose and sodium and must be swallowed whole.
• Keep in the original packaging until use to protect from moisture.

Tablet

Route: Oral

Strengths: 50 mg + 100 mg