People on methadone can succeed on hepatitis C treatment

Opiate users on methadone maintenance therapy can be successfully treated for chronic hepatitis C and can achieve outcomes similar to those of people not on methadone, according to data presented at the 13^th European AIDS Conference last week in Belgrade.

Shared use of injection drug equipment is a major risk factor for both HIV and hepatitis C virus (HCV) infection; an estimated 30% of people with HIV also have hepatitis C. But some clinicians have been reluctant to treat active or former drug users for hepatitis C, largely due to concern about suboptimal adherence and poor outcomes.

Karin Neukam from Hospital Universitario de Valme in Seville, Spain, and colleagues compared treatment response amongst 214 hepatitis C patients - a majority of them injection drug users - who started treatment with pegylated interferon plus ribavirin between January 2003 and May 2010. Just over one-third of participants (38%) were on methadone maintenance whilst 62% were not.

Most participants were men (88% in the methadone group, 77% in the non-methadone group) and the average age was about 42 years. About 25% in both arms were HIV-positive. Methadone recipients were slightly less likely to have the favourable IL28B "CC" gene pattern and more likely to have liver cirrhosis, but were significantly less likely to have hard-to-treat hepatitis C genotypes 1 or 4.

Almost all participants in both study groups reported 80% or better adherence to hepatitis C therapy. Rates of sustained virological response (SVR) - or continued undetectable HCV viral load 24 weeks after completion of treatment - were similar in the methadone and non-methadone groups.

In an intention-to-treat analysis, the overall SVR rate was 48% in both groups. Amongst people with the more difficult-to-treat HCV genotypes 1 or 4, 35% of methadone recipients and 42% of non-methadone patients achieved SVR. Amongst people with easier-to-treat genotypes 2 or 3, the corresponding rates were 69% and 65%. Neither difference was statistically significant. The same pattern was seen in an on-treatment analysis, with overall SVR rates of 57% and 59%, respectively.

Participants with HIV/HCV coinfection, high baseline HCV viral load, unfavourable IL28B gene pattern and cirrhosis at study entry were less likely to achieve sustained response. Other factors including gender, history of injection drug use, depression and ribavirin dose were not significantly associated with treatment response.

Other outcomes in addition to sustained response were also similar in the methadone and non-methadone groups: post-treatment relapse (11% vs 12%, respectively), virological breakthrough (1% in both groups), null response (22% vs 21%, respectively) and treatment discontinuation due to adverse events (5% vs 7%, respectively).

"The efficacy of HCV therapy in methadone maintenance therapy patients is similar to that found in subjects not taking methadone," the researchers concluded. "Methadone maintenance therapy patients should be equally considered for treatment with pegylated interferon plus ribavirin."

These findings indicate that methadone maintenance should not be considered a contraindication to hepatitis C treatment. Session moderator Stefan Mauss from Heinrich-Heine University said data like these are especially needed in Eastern Europe to convince clinicians and others that hepatitis C in patients on methadone can be successfully treated.