Response to treatment of hepatitis C in individuals with a recent history of intravenous drug abuse.

OBJECTIVE: The aim of this study was to determine the rate of sustained response (SR) to high-dose daily interferon (IFN) therapy in prior drug abusers with chronic hepatitis C. This was a retrospective matched cohort study conducted at a tertiary care university hospital in a large urban area.
METHODS: The 120 individuals in each cohort were treated by the same physicians at the same facility, using the same treatment protocol and management procedures. Each patient received 5 million units of IFN daily for at least 1 yr and usually longer.
RESULTS: Both groups achieved a similar rate of SR (no i.v. drug abuse, 37% vs i.v. drug abuse, 33%). The end of treatment (ET) response rate was unexpectedly higher in the drug-abusing population as compared to that non-drug-abusing control subjects but fell during the follow-up period to achieve an SR similar to that of the non-drug-abusing controls. The side effects of IFN therapy were no greater in the prior drug abusing population than in the controls, although many in the drug-abusing group increased their dose of methadone to counteract IFN side effects.
CONCLUSIONS: The SR rate achieved by intravenous drug abusers to high-dose, daily IFN is similar to that in a non-drug-abusing HCV positive population. Recent use of illicit drugs within a 6-month period of starting IFN therapy or continued methadone use during treatment does not seem to impair the response to IFN when the results are compared with those of a matched cohort of non-drug-abusing controls.