Hepatitis C drugs are given as combinations. Interferon-free direct-acting antiviral treatment consists of drugs of two or three different types. Each type of drug is designed to interrupt a different stage in the life cycle of HCV. By targeting different stages, a treatment combination has a better chance of stopping the production of new viruses. If one type of drug is used hepatitis C viruses are highly likely to develop resistance to it. If two or more types of drugs are used, it is much more difficult for viruses to emerge which are resistant to both drugs. Direct-acting antivirals target three different parts of the HCV life cycle to stop the production of new viruses:

• Protease inhibitors such as paritaprevir (part of Viekirax & Exviera) glecaprevir (part of Maviret), grazoprevir (part of Zepatier) and voxilaprevir (part of Vosevi).
• NS5A inhibitors such as ledipasvir (part of Harvoni), pibrentasvir (part of Maviret) daclatasvir (Daklinza), velpatasvir (part of Epclusa) and elbasvir (part of Zepatier).
• NS5B polymerase inhibitors: sofosbuvir (Sovaldi, also in Harvoni and Epclusa).
• NS5B non-nucleoside inhibitors: dasabuvir (part of Viekirax).

Ribavirin

Ribavirin is an antiviral drug and is taken daily in tablet form. As an individual medication, ribavirin has almost no effect on hepatitis C viruses. When combined with interferon, however, it enhances the effect of interferon, improving the chances of curing hepatitis C. Ribavirin also improves the effect of some direct-acting antiviral combinations in people who have hepatitis C that is harder to cure, such as people with advanced cirrhosis and those with post-liver transplant recurrence of hepatitis C.

Interferon

Interferon is a substance produced by the body when viruses or bacteria enter the body. Using interferon as a treatment stimulates the body’s natural immune defences. Interferon can be injected to stimulate an immune response. Pegylated interferon alpha is used in the treatment of hepatitis C. It has a type of protective coating, which prevents it being broken down too quickly in the body. This helps to maintain constant levels of interferon, improving the chances of successful treatment. Pegylated interferon is rarely used nowadays in  the treatment of hepatitis C because direct-acting antivirals are better tolerated, more effective and cure most people after 8-12 weeks of treatment.