Combination treatment with interferon and ribavirin for chronic hepatitis C.

Interferon was the first drug shown to be effective in patients with chronic hepatitis C, but initial treatment regimens achieved sustained loss of virus in only a small minority of patients. The combination of IFN with ribavirin now makes sustained response rates of 30% to 40% possible. This is quite a remarkable achievement for a pharmacologic treatment of a chronic viral infection. It is now reasonable to assume that early treatment and eradication of chronic hepatitis C might reduce the growing burden of hepatitis C and its complications on the healthcare system. Future researchers will strive to optimize combination treatment regimens. Longer treatment courses and intensified induction regimens using either daily dosing, high doses, or both may improve long-term response, but this remains speculative. Other forms of IFN may improve response or increase the ease of drug administration. Conjugation of biologic compounds to polyethylene glycol can result in significant prolongation of plasma half-life while maintaining the properties of the parent molecule. Some biologic properties may be altered, however, so pegylated IFN must continue to be evaluated in clinical trials. There is limited clinical data on other recombinant or natural interferons in combination with oral ribavirin, however, these may prove to be equally effective. Combinations of IFN with one or more other antiviral, anti-inflammatory, or immune modulatory agents will need to be studied. Although amantidine is not effective against hepatitis C as a single agent or in combination with IFN, the combination of IFN, ribavirin, and rimantidine has been shown to have antiviral activity superior to the IFN-ribavirin combination against influenza virus and possibly against HCV.