摘要：Objectives. To examine the relationship between benzodiazepine (BZD) use and HCV seroconversion in 2 linked prospective cohorts of persons who inject drugs (PWID). Methods. We examined prospective cohorts of 440 PWID (baseline BZD users: n = 102; 23.2%) from the AIDS Care Cohort to Evaluate Access to Survival Services (ACCESS) and the Vancouver Injection Drug Users Study (VIDUS) cohorts, followed-up from 1996 to 2013 in Vancouver, Canada. Results. At baseline, the prevalence of HCV was higher among those who used BZD (80.5% vs 61.5%; P < .001). After adjustment, BZD use remained independently associated with increased rates of HCV seroconversion (adjusted rate ratio = 1.67; 95% confidence interval = 1.05, 2.66). Conclusions. BZD use is independently associated with HCV seroconversion in a population of PWID. Originally marketed more than 40 years ago as a safer alternative to existing sedatives, benzodiazepines (BZD) are commonly used for a broad range of complaints, including anxiety, agitation, depression, insomnia, seizure disorders, spasticity, and alcohol withdrawal. 1 As a result, BZD are among the most frequently prescribed medications in North America, with 5.2% of adult Americans reporting taking BZD in recent surveys. 2 Despite this widespread use, there remains a paucity of evidence supporting their effectiveness for many of these indications. 3,4 Complicating the debate on BZD efficacy is an increasing appreciation for the harms associated with both short- and long-term use, including drowsiness, ataxia, amnesia, and cognitive impairment. 5,6 These well-described side effects can lead to downstream consequences, including an increased risk of falls, fractures, and motor vehicles accidents. 7,8 An additional concern is physical dependency, which often requires an extended tapering schedule to safely wean patients. Although the adverse effects of BZD use are relatively common, their euphoric properties have led to widespread issues of abuse, particularly in subpopulations with a history of alcohol abuse. 9,10 Polysubstance users are at particularly high risk for BZD abuse because they frequently use BZDs to enhance the high of other drugs or to treat the adverse effects of drug use and the symptoms of drug withdrawal. 11 In these populations, BZD use has been correlated with more extensive illicit drug use, higher risk of accidental overdose, more psychiatric comorbidities, poorer health, and increased overall mortality. 12–16 Reduction in BZD use has been associated with a reduction in harm in these patients, suggesting that BZD use itself may be driving the poorer clinical outcomes. 13 HCV is a blood-borne pathogen that is estimated to affect 2% to 3% of the world’s population, or between 130 million and 170 million people. 17 The virus is commonly contracted through use of contaminated syringes during injection drug use, and approximately 10 million of the 16 million persons who inject drugs (PWID) worldwide are believed to be HCV antibody positive. 18 Although no vaccines exist to prevent HCV, novel treatments in the form of direct-acting antiviral agents have recently been developed and have had excellent results compared with the older regimens of ribavirin and pegylated interferon. 19 This technology has the potential to transform the landscape of HCV treatment within North America, but these medications are extremely expensive and remain out of reach for most individuals, underscoring the continued importance of HCV prevention efforts. Several previous studies of PWID have noted that the abuse of BZD has been linked to an increase in risky behaviors such as needle sharing and unprotected sex. 20,21 It has additionally been observed that BZD use is associated with a higher prevalence of HCV infection. 22–24 Because of this association between BZD use and HCV, we examined the hypothesis that BZD use leads to an increased rate of HCV seroconversion in 2 linked prospective cohorts of HCV-negative PWID in a Canadian setting.
