7-11 November 2010, Tenth International Congress on Drug Therapy in HIV Infection, Glasgow, UK The possibility of re-infection is often cited as a reason for not initiating treatment in injection drug users (IDUs). Recent observational data suggest that the rate of re-infection may be reduced following spontaneous or treatment-induced virologic clearance, although such data are often retrospective and incomplete. With this in mind, we have undertaken a systematic, prospective study to evaluate the incidence of HCV viremia in IDUs at risk of new infection. We identified a cohort of IDUs receiving care at the Pender Community Health Centre on Vancouver's Downtown East Side. Potential subjects were identified as either never having been infected with HCV (non-infected arm), having spontaneously cleared the virus (spontaneous arm), or having achieved a sustained virologic response on antiviral treatment (SVR arm). A questionnaire to identify demographics, health status, risk behavior and drug use was administered at baseline and every 6 months, along with blood tests to identify their HCV status. A total of 73 subjects met criteria for inclusion in the study: 20 in the non-infected, 30 in the spontaneous and 23 in the SVR arms respectively. Their mean age was 44.7, 17 were female, 9 were HIV-positive. There were no significant differences among the 3 groups with respect to age, ethnicity, source of income, unstable housing and being on opiate maintenance program. Over a mean follow-up period of 10.3 months, 20% of the non-infected group became viremic, as compared to 0% of the other two groups (p=0.04). Injecting drugs in past 30 days (p=0.05), heroin (p=0.015), amphetamines (p=0.05), and combined drugs use (p=0.001) were significantly higher in the non-infected arm compared to SVR arm. There were no significant differences in drug use and risk behavior between non-infected and spontaneous arms. Our study shows that viremic HCV infection is more likely to occur in those who have never been previously infected, and that this susceptibility to infection cannot be completely explained by an increase in risk behavior, at least as compared to individuals who have cleared their viremia spontaneously. In addition, HIV co-infection is not a significant factor associated with recurrent HCV viremia. Whether a decreased rate of viremia following SVR relates to some host-related protective factors or is due to a change in IDU-related risk as a result of engagement in the health care system is currently under study.

7‐11 November 2010, Tenth International Congress on Drug Therapy in HIV Infection, Glasgow, UK

BACKGROUND AND AIM:There are few studies investigating the treatment of hepatitis C virus (HCV) infection in current and former drug users. With this in mind, we sought to evaluate the antiviral efficacy of interferon alpha-2b (IFN alpha-2b) or pegylated-interferon alpha-2b (PEG-IFN alpha-2b) and ribavirin (RBV) in injection drug users (IDU) enrolled in a directly observed therapy (DOT) program, as measured by sustained virologic response (SVR). METHODS:Viremic HCV-infected IDU, with alanine aminotransferase (ALT) >1.5x upper limit of normal (ULN) were offered 24-48 week (based on HCV genotype) therapy with RBV (800-1200 mg/day, based on weight) along with IFN alpha-2b (3 million IU thrice weekly) replaced by PEG-IFN alpha-2b (1.5 ìg/kg once weekly) as it became available. All injections were directly observed. The primary endpoint was SVR. RESULTS:Overall, 40 patients (33 males) received IFN alpha-2b (12) or PEG-IFN alpha-2b (28), 55% with HCV genotypes 2 or 3. Only 14 discontinued therapy, 5 due to toxicity, 6 due to illicit drug use and 3 did not achieve an early virologic response. In an intent-to-treat analysis, the overall SVR was 55% (22/40), 64% (14/22) in subjects with genotypes 2/3. There was no significant difference in response rates among those with >6 (50%) or <or=6 months (64%) drug abstinence (P = 0.51) or among those with (53%) and without (57%) intercurrent drug use (P = 0.99); however, frequent users (n = 9) had a decreased SVR (22%) when compared with occasional users (n = 10, 80%, P = 0.12). CONCLUSION:Treatment of HCV in current and former IDU within a multidisciplinary DOT program can be successfully undertaken, resulting in SVR similar to those in randomized controlled trials.

The objective of this prospective, observational clinical study was to evaluate the safety and efficacy of once-daily and twice-daily directly observed therapy (DOT) in human immunodeficiency virus (HIV)-infected patients undergoing methadone treatment. Methadone and highly active antiretroviral therapy (HAART) were dispensed daily as DOT, with patients in the twice-daily HAART group self-administering the second dose. Clinical and laboratory end points were monitored, along with the impact of ongoing cocaine use. We studied 54 patients coinfected with HIV and hepatitis C virus. At baseline, the median virus load was 111,000 copies/mL, and the median CD4+ cell count was 165 cells/mm3. After a median of 24 months, 17 of 29 patients in the once-daily HAART group and 18 of 25 in the twice-daily HAART group had virus loads of <400 copies/mL, regardless of ongoing cocaine use. Thirty-two patients required methadone dose adjustment, which was managed without modification of HAART. Treatment-limiting hepatic toxicity was rare. A DOT program of coadministered methadone and HAART can be implemented with good results, even for patients who continue to use cocaine.