2.1 Testing Prior to the Initiation of Therapy

• Test all patients for evidence of current or prior HBV infection by measuring hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) before initiating HCV treatment with VIEKIRA PAK [see Warnings and Precautions (5.1)].
  
• Prior to initiation of VIEKIRA PAK, assess for laboratory and clinical evidence of hepatic decompensation [see Warnings and Precautions (5.2 and 5.3)].

2.2 Recommended Dosage in Adults

VIEKIRA PAK is ombitasvir, paritaprevir, ritonavir fixed dose combination tablets copackaged with dasabuvir tablets.

The recommended oral dosage of VIEKIRA PAK is two ombitasvir, paritaprevir, ritonavir tablets once daily (in the morning) and one dasabuvir tablet twice daily (morning and evening). Take VIEKIRA PAK with a meal without regard to fat or calorie content [see Clinical Pharmacology (12.3)].

VIEKIRA PAK is used in combination with ribavirin (RBV) in certain patient populations (see Table 1). When administered with VIEKIRA PAK, the recommended dosage of RBV is based on weight: 1000 mg/day for subjects <75 kg and 1200 mg/day for those ≥75 kg, divided and administered twice-daily with food. For ribavirin dosage modifications, refer to the ribavirin prescribing information.

For patients with HCV/HIV-1 co-infection, follow the dosage recommendations in Table 1. Refer to Drug Interactions (7) for dosage recommendations for concomitant HIV-1 antiviral drugs.

Table 1 shows the recommended VIEKIRA PAK treatment regimen and duration based on patient population.

2.3 Use in Liver Transplant Recipients

In liver transplant recipients with normal hepatic function and mild fibrosis (Metavir fibrosis score 2 or lower), the recommended duration of VIEKIRA PAK with ribavirin is 24 weeks, irrespective of HCV genotype 1 subtype [see Clinical Studies (14.6)]. When VIEKIRA PAK is administered with calcineurin inhibitors in liver transplant recipients, dosage adjustment of calcineurin inhibitors is needed [see Drug Interactions (7)].

2.4 Hepatic Impairment

VIEKIRA PAK is contraindicated in patients with moderate to severe hepatic impairment (Child-Pugh B and C) [see Contraindications (4), Warnings and Precautions (5.2), Use in Specific Populations (8.6), and Clinical Pharmacology (12.3)].