Background Although the harms of prescription drug diversion are of growing international concern, the potential impact of prescription drug use on HIV infection has not been well assessed. We evaluated whether benzodiazepine use was associated with HIV seroconversion among a cohort of persons who inject drugs (PWID) in a Canadian setting. Methods Between May, 1996 and November, 2013, data were derived through a prospective cohort study of PWID in Vancouver, Canada. A total of 1,682 baseline HIV negative participants were followed for a median of 79.5 months (interquartile range: 32.1 – 119.1), among whom 501 (29.8%) reported benzodiazepine use at baseline, and 176 seroconverted during follow-up, equal to an incidence density of 1.5 (95% Confidence Interval [CI]: 1.3 – 1.7) cases per 100 person-years. Poisson regression with time-dependent variables was used to assess whether benzodiazepine use was associated with the time to HIV seroconversion. Results After adjustment for potential confounders, benzodiazepine use (Adjusted Rate Ratio: 1.50; 95% CI: 1.01 – 2.24) was independently associated with a higher rate of HIV seroconversion. Conclusions Benzodiazepine use was an independent risk factor for HIV seroconversion among PWID in this setting. Greater recognition of the safety concerns related to benzodiazepine medications including d iversion are needed.

Background and Aims Injecting illicit drugs in public settings has been linked to a higher risk of a range of drug-related harms, including overdose and HIV infection. However, the factors associated with public injecting among HIV-positive individuals have not been previously explored. We investigated the links between public drug injecting, drug-related harm, and HIV treatment measures among a cohort of HIV-positive persons who inject drugs (PWID) in a Canadian setting. Methods We used data from a prospective cohort of HIV-positive PWID recruited from community settings in Vancouver, Canada, linked to comprehensive clinical monitoring data in the context of an ongoing Treatment-as-Prevention (TasP) initiative to examine harms associated with public injecting. We used generalized linear mixed-effects analyses to identify longitudinal factors associated with self-reported public drug injection. Results Between 2005 and 2014, 626 HIV-seropositive PWID were recruited, of whom 213 (34%) reported public injection in the preceding 180 days. In a longitudinal multivariable model, public injection was positively associated with daily heroin injection (Adjusted Odds Ratio [AOR] = 2.63), incarceration (AOR = 1.78), and detectable plasma HIV-1 RNA viral load (VL, AOR = 1.42). Conclusions Public injecting was linked to numerous drug-related harms among HIV seropositive PWID in this setting. Given its link with detectable VL, an important marker of poor HIV treatment outcomes, our findings support prioritizing individuals engaged in public injecting with harm reduction strategies as well as clinical and social supports as a part of TasP-based efforts to prevent HIV-related morbidity and mortality, and HIV transmission.

Background: Using a clinical case example, we describe and discuss the use of oral naltrexone as a novel treatment strategy for nitrous oxide use. Nitrous oxide is an inhalant drug that is readily available and legally obtained. Though frequency of reported cases of substance use disorder for nitrous oxide is low, previous case reports have described severe neurological and psychiatric harms associated with chronic use. Despite this, evidence for pharmacotherapy is currently lacking. Clinical studies have shown variable efficacy for naltrexone across a number of substances including alcohol, nicotine, and stimulants. Case: We present here a case of a 41-year-old man with a substance use disorder for nitrous oxide who was reportedly using of up to four hundred 8 g canisters of nitrous oxide per day. Oral naltrexone was initiated at 50 mg daily in an attempt to decrease cravings. The dose was subsequently titrated to 100 mg daily, resulting in a decrease in nitrous oxide use to less than sixty 8 g canisters per week over a 1-month timeframe. Discussion: Previous literature surrounding naltrexone provides both a plausible mechanism of action for craving reduction as well as a precedent for its use across a number of substances. To our knowledge, use of naltrexone for nitrous oxide use has not been previously described. While clinical studies are currently lacking, this case highlights naltrexone as a possible treatment strategy for nitrous oxide use, with potential to reduce significant harms associated with chronic use.

No abstract