LAUSR

Substance users have the highest prevalence of hepatitis C virus (HCV) infection but have rarely been treated, largely because of their mistrust of the health care system, misconceptions about the consequences of the infection, and concerns regarding interferon‐related side effects. With the development of highly efficacious, interferon‐free therapeutic regimens without significant side effects, the concept of colocating HCV and substance use treatment would appear to be highly feasible. This process has been further facilitated by widespread clinical adaptation of noninvasive assays for fibrosis assessment, which could be performed routinely in substance use treatment facilities. The most commonly used noninvasive fibrosis assessment methods are serum marker indexes and transient elastography, both of which are very accurate in detecting cirrhosis or the absence of fibrosis, but much less successful in identifying intermediate fibrosis stages. The effect of drugs of abuse on the liver is not completely understood or sufficiently studied. There are no indications that heroin and cocaine affect fibrosis progression, but some recreational drugs (eg, alcohol and cannabis) can induce hepatic injury. In addition, knowledge gaps exist on the effect of impaired liver function on metabolism or transport of agents used to treat substance disorders as well as their interactions with HCV antivirals.