ombitasvir, paritaprevir and ritonavir

J05AP53

Forms & Strengths

Fixed-dose combination tablet: ombitasvir 12.5 mg, paritaprevir 75 mg, ritonavir 50 mg

Adult Dosing

Hepatitis C virus genotype 1 infection: One tablet orally twice daily with food, used in combination with other agents (e.g., dasabuvir with or without ribavirin) for 12 or 24 weeks depending on patient population and cirrhosis status

Pediatric Dosing

Safety and efficacy have not been established in pediatric patients under 18 years of age

Indications

Treatment of chronic hepatitis C virus (HCV) genotype 1 infection, including patients with compensated cirrhosis

Mechanism of Action

Ombitasvir is an HCV NS5A inhibitor preventing viral replication and assembly
Paritaprevir is an HCV NS3/4A protease inhibitor blocking viral polyprotein cleavage
Ritonavir is a pharmacokinetic enhancer inhibiting CYP3A4-mediated metabolism of paritaprevir to maintain systemic drug levels

Contraindications

Moderate to severe hepatic impairment (Child-Pugh B or C)
Co-administration with drugs highly dependent on CYP3A for clearance and associated with serious toxicities
Co-administration with strong inducers of CYP3A or CYP2C8
Known hypersensitivity to ritonavir or any components of the formulation

Adverse Reactions

Fatigue
Nausea
Pruritus
Insomnia
Asthenia
Elevated serum ALT and AST (risk of hepatotoxicity, particularly with ethinyl estradiol-containing products)

Drug Interactions

Contraindicated with strong CYP3A inducers (e.g., carbamazepine, phenytoin, rifampin, St. John's wort) which significantly decrease therapeutic concentrations
Contraindicated with ethinyl estradiol-containing medications due to high risk of ALT elevations
Co-administration with potent CYP3A inhibitors may increase concentrations of paritaprevir
Potential for significant pharmacokinetic interactions with statins (e.g., simvastatin, atorvastatin), immunosuppressants, and sedatives requiring dose adjustment or monitoring

Curated Content: Needs Vetting Before Put to Clinical Use