Provided by Clinical Care Options
In many ways, people who inject drugs (PWID) represent a “forgotten” group of patients eligible for hepatitis C virus (HCV) treatment. Generally, they have been excluded from clinical trials and HCV treatment guidelines. When they have approached clinicians for treatment, they have been told that once they stop using drugs for more than 6 months, they can think about treatment. Preconceptions about low rates of adherence, inability to attend appointments, increased susceptibility to adverse effects, and the potential for high rates of reinfection have limited providers’ willingness to reach out to and treat this at-risk population. Concerns about HIV coinfection, interactions between drugs—both prescribed and illicit—and liver damage due to heroin or methadone have further limited interest in treating PWID.
Recently published international recommendations from the International Network on Hepatitis in Substance Users, of which I am a coauthor, are intended to supplement existing guidelines and address many of these issues. To implement these recommendations, we have to address obstacles that may interfere with the initiation of treatment.
Breaking Down the Barriers
PWID continue to experience high rates of HCV infection in developed countries. The damage associated with HCV infection is known to be accelerated by factors such as age, ongoing moderate or heavy alcohol use, HIV coinfection, obesity, and insulin resistance. However, there is no evidence that fibrosis is accelerated by methadone or heroin use and little is known about the effect of methamphetamine. Similarly, whereas active PWID were excluded from the pivotal trials of the currently available direct-acting antivirals, results from separate trials indicate that methadone/buprenorphine can be coadministered with direct-acting antivirals. Finally, treatment for HCV should not significantly affect treatment for drug dependency nor lead to an increase in drug use.
If the decision is made to treat PWID for HCV, will they adhere to therapy or will they fail to complete their course of treatment? The few studies addressing HCV treatment in a setting of active drug use indicate that PWID can be treated successfully. My experience is similar to that described by Graham Foster: When PWID are carefully identified and counseled, they stay with therapy almost as readily as any other population.
What about reinfection? Many providers believe that PWID actively using drugs, even intermittent users, are just going to get reinfected, negating previously successful treatment efforts. As it happens, this does not appear to be the case. Actively using PWID certainly should be counseled about the risks associated with certain behaviors and the potential for reinfection, but the reinfection rates associated with active drug use may actually be quite low based on a recent review of available studies. These data suggest that there is no need to avoid treating HCV in PWID for fear that it will be necessary to repeat the process.
Some providers have raised concerns about the possibility of poor adherence among this patient population. Taking into consideration the high costs of HCV therapy and the potential for transmitted resistance by nonadherent patients, many providers may be reluctant to initiate therapy in this population. However, this perception is not borne out by the evidence that indicates PWID are no less likely to adhere to therapy than other patients. Furthermore, in the era of direct-acting antivirals, resistance may be a less of a concern due to their higher barrier to resistance.
Overcoming Our Own Preconceptions
There are numerous strategies we can employ to improve outcomes for PWID. First, we have to decide to treat these patients, and to make that decision, we need to recognize that what appear to be barriers are not necessarily so. There is no denying that there are challenges to the treatment of HCV in this population. However, when barriers are systematically identified and addressed within a supportive, multidisciplinary environment, PWID can be successfully treated for HCV infection. Also, reinfection is lower than one might expect. This is not to deny that challenges do exist, but they are not insurmountable. We can begin by overcoming our own preconceptions, which will allow us to implement appropriate strategies and successfully treat these patients.
I am keen to hear your thoughts and experiences in treating HCV in PWID. Do you treat actively using PWID or ask them to cease drug use? How have you approached the treatment of PWID? Is there a particular strategy that has been successful for you in treating PWID?