Treatment of hepatitis C virus and HIV co-infections.

Hepatitis C coinfection is common in patients with HIV, particularly in injection-drug users. Hepatitis C virus levels tend to be higher in coinfected patients, and histologic progression is more rapid than in patients with HCV alone. The efficacy of interferon monotherapy in HIV patients with an adequate CD4 cell count is comparable to that observed in patients without HIV. The combination of interferon plus ribavirin and pegylated interferon will further improve response rates. Interferon therapy is associated with leukopenia and a decrease in absolute CD4 cell count. Some concern remains that ribavirin might reduce the activity of pyrimidine analogues such as zidovudine and stavudine, and HIV-RNA levels should be followed when these medications are given concurrently. It is hoped that in time, new drug development will make the multiple-drug therapeutic strategy that has been highly successful in the management of HIV feasible for the treatment of HCV.