Adult: In patients with chronic hepatitis C genotype 1 or 4 (treatment-naive or treatment-experienced, with or without compensated cirrhosis): 100 mg bid for 24 weeks, in combination with daclatasvir, or daclatasvir, peginterferon alfa, and ribavirin. Missed dose: Skip dose if >8 hours before the next dose; if <8 hours before the next dose, take the missed dose and resume normal dosing schedule. Dose modification, interruption and discontinuation is not recommended. Refer to peginterferon alfa and ribavirin detailed product guidelines for dose modifications.
Patient on hemodialysis: 100 mg bid.
100 mg once daily.
Moderate or severe (Child-Pugh class B or C): Contraindicated.
Hypersensitivity. Decompensated hepatic disease. Moderate or severe hepatic impairment (Child-Pugh class B or C). Concomitant use with CYP3A4 inducers or inhibitors, thioridazine, or OATP1B1 inhibitors.
Patient with hepatitis B virus (HBV) or HIV co-infection, liver-transplant recipients. Severe renal and mild hepatic impairment. Pregnancy and lactation. Not intended for use as monotherapy.
Blood and lymphatic system disorders: Anaemia, neutropenia, hyperbilirubinaemia. Gastrointestinal disorders: Nausea, diarrhoea, constipation, abdominal pain. General disorders and administration site conditions: Fatigue, asthenia, influenza-like illness, irritability, pain. Investigations: Increased serum AST, ALT. Musculoskeletal and connective tissue disorders: Arthralgia, myalgia, back pain. Nervous system disorders: Headache, dizziness. Psychiatric disorders: Insomnia, depression. Respiratory, thoracic and mediastinal disorders: Cough, dyspnoea, nasopharyngitis. Skin and subcutaneous tissue disorders: Pruritus, rash, alopecia, dry skin. Potentially Fatal: Hepatitis B virus reactivation, resulting in fulminant hepatitis or hepatic failure (in patients with HBV co-infection).
Obtain hepatitis B surface antigen (HbsAg) and hepatitis B core antibody (anti-HBc) prior to initiation of therapy to test for evidence of current or prior HBV infection. Monitor liver enzyme and HCV-RNA at baseline, during and after treatment, and as clinically indicated. Monitor clinical and laboratory signs of HBV reactivation. Perform routine pregnancy tests and ensure proper use of birth control prior to therapy.
May increase serum concentration of dabigatran, TCA, dextromethorphan, digoxin, HMG-CoA reductase inhibitors. May decrease serum concentration of oral contraceptives, midazolam. Potentially Fatal: Decreased plasma concentration and therapeutic effect with moderate or strong CYP3A4 inducers (e.g. carbamazepine, phenobarbital, phenytoin, rifampicin, nafcillin, bosentan, dexamethasone, efavirenz, etravirine, nevirapine, modafinil). Increased plasma levels with moderate or potent CYP3A4 inhibitors (e.g. fluconazole, clarithromycin, diltiazem, verapamil, atazanavir, cobicistat or cobicistat-containing regimen), organic anion transport polypeptides (e.g. ciclosporin, gemfibrozil). May cause cardiac arrhythmia with thioridazine.
Increased absorption with high-fat meal. Decreased serum concentration with St John’s wort.
Description: Asunaprevir is a hepatitis C virus (HCV) nonstructural protein 3/4A (NS3/4A) serine protease inhibitor. It binds to the NS3/4A protease active site, thereby inhibiting viral replication activity. Pharmacokinetics: Absorption: Rapidly absorbed. Increased absorption with high-fat meal. Absolute bioavailability: 9.3%. Time to peak plasma concentration: 1-4 hours. Distribution: Volume of distribution: 194 L. Plasma protein binding: >99%. Metabolism: Undergoes oxidative metabolism in the liver mainly by CYP3A4 enzyme, to unchanged drug and metabolites. Excretion: Mainly via faeces (approx 84%, primarily as metabolites); urine (<1%, primarily as metabolites). Elimination half-life: 17-23 hours.