best practice

Pre-exposure prophylaxis of HIV in adults at high risk was found in an evidence review (NHS, 2016) to be effective in:

• reducing the relative risk of acquiring HIV infection by the following amounts in men or transgender women who have sex with men,
  • 44 % compared with placebo (1RCT ‘iPrEx’, n=2 441; Truvada given daily; number needed to treat [NNT] 62 per year)
  • 86 % compared with no prophylaxis (1 RCT ‘PROUD’, n=523; Truvada given daily; NNT 13 per year)
  • 86 % compared with placebo (1 RCT ‘IPERGAY’, n=400; Truvada given 'on demand'; NNT 18 per year)
• reducing the relative risk of acquiring HIV infection in serodiscordant heterosexual couples by 75 % compared with placebo (1 RCT ‘Partners PreP’, n=3 136, once-daily Truvada, mITT population; NNT 68 per year).

A review of reviews (MacArthur et al., 2014, N=25 reviews), without meta-analysis, concluded that there is:

• tentative evidence to support the effectiveness of outreach including IEC activities in reducing injecting risk behaviour (N=28 studies, 18 positive, 10 no association).

Opioid substitution treatment was found sufficiently supported by evidence in a synthesis of 4 narrative reviews (Malta et al.,2008; WHO, 2007b, Tilson et al., 2007, Lucas et al., 2006, cited in EMCDDA - ECDC 2011) in:

• improving the effectiveness of anti-retro-viral treatment in HIV positive opioid users.

Educational and training interventions complemented by take-home naloxone has been found to be effective in systematic review of 21 studies (EMCDDA, 2015) in:

• decreasing overdose-related mortality (1 interrupted time-series study, N= 2912, adjusted RR 0.54, 95 % CI 0.39–0.76).

Intranasal administration of naloxone was found in a review with meta-analysis (Yousefifard et al., 2020) to be as effective as intramuscular/intravenous administration in the pre-hospital management of opioid overdose:

• the success rate (defined as the recovery of patients’ consciousness and spontaneous respiration) of the intranasal and intramuscular/intravenous administration of naloxone was 82.54% (95% CI: 57.97 to 97.89%) and 80.39% (95% CI: 57.38 to 96.04%) respectively with no difference between the two routes (OR=1.01; 95% CI: 0.42 to 2.43; P=0.98).
• the prevalence of major side-effects was non-significant for both intranasal (0.00%) and intramuscular/intravenous (0.05%) routes and there was no difference in the prevalence of major (OR=1.18; 95% CI: 0.38 to 3.69; P=0.777) and minor (OR=0.64; 95% CI: 0.17 to 2.34; P=0.497) side-effects between the two routes.

The odds of needing a rescue dose was 2.17 times higher for intranasal naloxone than intramuscular/intravenous naloxone (OR=2.17; 95% CI: 1.53 to 3.09; P<0.0001), however since it does not require intravenous access and its re-administration does not cause serious complications, this limitation does not seem major enough to prevent its use.

European guidelines (EASL, 2015) recommend to provide treatment to drug users on an individualized basis  and delivering it within a multidisciplinary setting.

Opioid substitution treatment is not a contraindication to HCV treatment.

Pharmacy-based needle and syringe programmes (NSPs) were found in a systematic review with meta-analysis (Sawangjit et al., 2016, 14 observational studies, N= 7 035 PWID) to be effective in:

• reducing risk behaviours among people who inject drugs when compared to those with no NSP available (OR = 0.50, 95 % CI = 0.34–0.73) and sensitivity analyses, excluding studies with a serious risk of bias (OR = 0.52, 95 % CI = 0.32–0.84).

A review of reviews (MacArthur et al., 2014, N=25 reviews), without meta-analysis, concluded that there is:

• sufficient evidence to support the effectiveness of NSPs in reducing self-reported injecting risk behaviour among IDUs (N=43 studies, 39 positive, 1 negative, 3 no association).

Opioid substitution treatment (OST) with methadone maintenance was found to be effective in systematic reviews (Mattick et al., 2009, Bargagli A.M. et al., 2007, Mathers et al., 2013) in:

• reducing the risk of death:
  • mortality (any cause): three RCTs (N= 435) (RR 0.493, 95 % CI, 0.06 to 4.23) (¹)
  • mortality (any cause): five observational studies (N= 69970) (RR 0.3795, 95 % CI 0.29 to 0.48)
  • mortality during in-treatment and off-treatment periods at follow-up: six observational studies (RR 2.52, 95 % CI 1.50 to 4.00)
  • reducing risk of overdose death for those retained in treatment compared to those waiting for treatment, those who have left treatment or those that are in detoxification treatment:
  • five observational studies (N=69 970) (RR 0.17, 95 % CI 0.05 to 0.63)

(¹): the measure from the RCT is not statistically significant, nevertheless the evidence when considered together with the results of the observational studies, is significant.

NSP programmes were found to be effective in a systematic review (Aspinall et al., 2014), in:

• reducing the transmission of HIV among people who inject drugs (pooled effect size 0.66 (95 % CI 0.43 to -1.01)  across  all  studies,  and  0.42  (95 % CI  0.22 to 0.81) across six higher quality studies)