Injecting drug users (IDUs)

CHC is hyperendemic among IDUs. There are several
challenging aspects that have to be considered before effective
antiviral therapy can be provided to this group of patients (Roy
2002):
– uptake of antiviral therapy is low in these patients,
depending on the phase of addiction (active/regular IDUs,
on maintenance therapy with methadone; past users;
abstinence)
– adherence to therapy is low
– side effects are frequent and difficult to manage in the
context of drug dependency
– there is a risk of relapse to drug use in patients who are
currently abstinent or on maintenance therapy even after
HCV therapy is started
– even after successful HCV eradication, there is a high risk of
reinfection in IDUs (Backmund 2001)
When treatment is indicated in IDUs, it should be provided as
soon as possible and during any phase of drug addiction, with
the same regimen (dose, duration) delivered to the non-drug
users. Treatment uptake and adherence to therapy is usually low
in active IDU and reinfection may occur. Treatment should
preferably be postponed until the patient is stabilized on
maintenance (methadone) therapy. Treatment of abstinent/past
users is associated with excellent adherence, being as effective as
in non-drug users (Wilkinson 2009). Psychiatric illnesses are
common among IDU and high awareness and early intervention
for psychiatric side effects during HCV treatment is important.