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:
inhibitors such as simeprevir (Olysio),
paritaprevir (part of Viekirax &
Exviera) and grazoprevir (part of Zepatier).
inhibitors such as ledipasvir (part of Harvoni),
ombitasvir (part of Viekirax &
Exviera), daclatasvir (Daklinza),
velpatasvir (part of Epclusa) and
elbasvir (part of Zepatier).
polymerase inhibitors: sofosbuvir (Sovaldi,
also in Harvoni and Epclusa).
non-nucleoside inhibitors: dasabuvir (part of Viekirax).
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 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 today 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.
Scarring of the liver – the structure of the liver is altered. See also
‘fibrosis’, which is moderate scarring. See also ‘compensated cirrhosis’ and
A treatment regimen that does not include pegylated interferon.
of the building blocks from which DNA and RNA are made.
The stage of hepatitis infection refers to the amount of liver scarring
(fibrosis) detected by biopsy. Usually measured on scales of 0 to 4, or 0 to 6
(higher numbers indicated more severe inflammation).
Instead of the three injections previously used, one injection a week is now