Usual Adult Dose for Chronic Hepatitis C

Viekira Pak:

• Dasabuvir: 250 mg orally twice a day (morning and evening)
• Ombitasvir/paritaprevir/ritonavir fixed-dose combination tablet: 2 tablets orally once a day (in the morning)

• Genotype 1a, without cirrhosis: Viekira Pak plus ribavirin OR extended-release tablets plus ribavirin for 12 weeks
• Genotype 1a, with compensated cirrhosis (Child-Pugh A): Viekira Pak plus ribavirin OR extended-release tablets plus ribavirin for 24 weeks
• For some patients based on prior treatment history: May consider Viekira Pak plus ribavirin OR extended-release tablets plus ribavirin for 12 weeks
• Genotype 1b, with or without compensated cirrhosis (Child-Pugh A): Viekira Pak OR extended-release tablets for 12 weeks
• Liver transplant recipients with normal liver function and mild fibrosis (Metavir fibrosis score 2 or lower), regardless of HCV genotype 1 subtype: Viekira Pak plus ribavirin OR extended-release tablets plus ribavirin for 24 weeks

• Recommended for therapy-naive or interferon-experienced patients, including those with HCV/HIV-1 coinfection
• The dosing recommendations for genotype 1a should be followed for patients with unknown genotype 1 subtype or with mixed genotype 1 infection.
• The manufacturer product information should be consulted for ribavirin dosing recommendations (if applicable), regarding dosing of concomitant HIV-1 antiviral drugs in HCV/HIV-1-coinfected patients, and regarding use with calcineurin inhibitors in liver transplant recipients.
• The manufacturer product information for ribavirin should be consulted regarding dose adjustments (if applicable).

• In genotype 1b-infected patients without cirrhosis or with compensated cirrhosis
• In combination with ribavirin: In genotype 1a-infected patients without cirrhosis or with compensated cirrhosis

Renal Dose Adjustments

Mild, moderate, or severe renal dysfunction: No adjustment recommended.

Comments:

• If required, the manufacturer product information for ribavirin should be consulted regarding use in patients with renal dysfunction.

Liver Dose Adjustments

Mild liver dysfunction (Child-Pugh A): No adjustment recommended.
Moderate to severe liver dysfunction (Child-Pugh B and C): Contraindicated

Precautions

US BOXED WARNING:

• RISK OF HBV REACTIVATION IN PATIENTS COINFECTED WITH HCV AND HBV: All patients should be tested for evidence of current/prior HBV infection before starting this product. HBV reactivation has been reported during or after completion of HCV direct-acting antiviral therapy in HCV/HBV-coinfected patients who were not receiving HBV antiviral therapy; some cases resulted in fulminant hepatitis, hepatic failure, and death. HCV/HBV-coinfected patients should be monitored for hepatitis flare or HBV reactivation during HCV therapy and posttherapy follow-up; appropriate patient management for HBV infection should be started as clinically indicated.

• If used with ribavirin: Contraindications to ribavirin
• Moderate to severe liver dysfunction (Child-Pugh B and C)
• Coadministration with drugs highly dependent on CYP450 3A for clearance and for which elevated plasma levels are associated with serious and/or life-threatening events, including alfuzosin, ranolazine, dronedarone, colchicine (in patients with renal and/or liver dysfunction), lurasidone, pimozide, ergotamine, dihydroergotamine, methylergonovine, ethinyl estradiol-containing products (e.g., combined oral contraceptives), cisapride, lovastatin, simvastatin, atorvastatin, everolimus, sirolimus, tacrolimus, lomitapide, efavirenz, oral midazolam, triazolam, sildenafil (for treatment of pulmonary arterial hypertension)
• Coadministration with drugs that are moderate or strong inducers of CYP450 3A and strong inducers of CYP450 2C8 and may lead to reduced efficacy of this product, including carbamazepine, phenytoin, phenobarbital, apalutamide, rifampin, St. John's wort
• Coadministration with drugs that are strong CYP450 2C8 inhibitors and may increase dasabuvir plasma levels and risk of QT prolongation, including gemfibrozil
• Known hypersensitivity to ritonavir (e.g., toxic epidermal necrolysis, Stevens-Johnson syndrome)

Dialysis

No adjustment recommended.

Other Comments

Administration advice:

• Before starting this product, test all patients for evidence of current/prior HBV infection; measure hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc).
• Before starting this product, assess for laboratory and clinical evidence of hepatic decompensation.
• Administer Viekira Pak with a meal, without regard to fat or calorie content.
• Must administer extended-release tablets with a meal; reduced virologic response and possible resistance development may occur if administered under fasting conditions.
• Swallow extended-release tablets whole; do not split, crush, or chew (may compromise performance, efficacy, and/or safety of product).
• For optimal release of dasabuvir, do not consume alcohol within 4 hours of taking the extended-release tablets.

• Store at or below 30C (86F).

• Viekira Pak is ombitasvir/paritaprevir/ritonavir fixed-dose combination tablets copackaged with dasabuvir tablets; each fixed-dose combination tablet contains ombitasvir 12.5 mg, paritaprevir 75 mg, and ritonavir 50 mg.
• Each fixed-dose combination extended-release tablet contains dasabuvir 200 mg, ombitasvir 8.33 mg, paritaprevir 50 mg, and ritonavir 33.33 mg.
• The manufacturer product information for ribavirin should be consulted for additional information (if applicable).

• Hepatic: For laboratory and clinical evidence of hepatic decompensation (before starting therapy); for clinical signs/symptoms of hepatic decompensation in cirrhosis patients; hepatic laboratory tests, including direct bilirubin, in cirrhosis patients (at baseline, during first 4 weeks of therapy, then as clinically indicated); ALT (if increases above baseline levels)

• Read the US FDA-approved patient information (Medication Guide) for this product and review the Medication Guide for ribavirin, if applicable.
• Watch for signs of liver inflammation/failure (e.g., early signs: fatigue, weakness, lack of appetite, nausea and vomiting; later signs: jaundice, onset of confusion, abdominal swelling, discolored feces); consult healthcare provider immediately if these symptoms develop.
• Take extreme care to avoid pregnancy during use of this product with ribavirin and within 6 months of stopping ribavirin in female patients and female partners of male patients; inform healthcare provider immediately in the event of pregnancy.
• Avoid missing doses and complete the entire course of therapy; do not remove tablets from daily dose pack until you are ready to take them.

Frequently asked questions

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