Tolerability of treatments for viral hepatitis

Interferon-alpha is the most widely used antiviral drug in chronic hepatiti s B and C, Tolerability is usually good and serious adverse effects are rar e. Most of the adverse effects are mild or transient and do not necessitate drug withdrawal. More than 90% of patients who are given interferon-alpha achieve 6 months to 1 year of treatment without serious adverse effects, Th e serious adverse effects usually occur in predisposed patients with pre-ex isting organ dysfunction. Nevertheless, careful selection of patients for t herapy and observation during therapy are recommended, Nucleoside analogues are promising drugs in the treatment of chronic hepati tis B through inhibition of viral DNA polymerase. Lamivudine has been licen sed for use in this indication. Its tolerability is excellent even when use d for periods of 1 year or more. The main concern is the relatively high in cidence of viral resistance resulting in breakthrough during or relapse aft er therapy. In the treatment of chronic hepatitis C, ribavirin, in combination with int erferon-alpha is currently the reference therapy. The main adverse effect i s haemolytic anaemia, which necessitates careful monitoring and adjustment of dosage in many cases. Recently, large trials showed the better efficacy of pegylated interferons as compared with standard interferon. The combinat ion of pegylated interferon with ribavirin is under evaluation.