This study assessed the prevalence and patterns of drug use among people living with HIV (PLHIV) in Spain. We conducted an observational cross-sectional study including 1401 PLHIV. Data were collected through 33 sites across Spain using an online computer-assisted self-administered interview. The survey measured use of illicit drugs and other substances, treatment adherence and health-related variables. To analyse patterns of drug use we performed cluster analysis in two stages. The most frequently consumed substances were: alcohol (86.7%), tobacco (55.0%), illicit drugs (49.5%), other substances (27.1%). The most prevalent illicit drugs used were cannabis (73.8%), cocaine powder (53.9%), and poppers (45.4%). Results found four clusters of PLHIV who used drugs. Two of them were composed mainly of heterosexuals (HTX): Cluster 1 (n = 172) presented the lowest polydrug use and they were mainly users of cannabis, and Cluster 2 (n = 84) grouped mostly men who used mainly heroin and cocaine; which had the highest percentage of people who inject drugs and presented the lowest level of treatment adherence (79.8±14.2; p < .0001). The other two clusters were composed mainly of men who have sex with men (MSM), who were mostly users of recreational drugs. Cluster 3 (n = 285) reported moderate consumption, both regarding frequency and diversity of drugs used, while Cluster 4 (n = 153) was characterized by the highest drug polyconsumption (7.4±2.2; p < .0001), and 4 grouped MSM who injected recreational drugs, and who reported the highest frequency of use of drugs in a sexual context (2.6±0.8; p < .0001) and rates of sexually transmitted infections (1.8±1.1; p < .01). This is the largest multi-centre cross-sectional study assessing the current prevalence and patterns of drug use among PLHIV in Spain. The highest prevalence of drug use was found among MSM, although HTX who used heroin and cocaine (Cluster 2) had the most problems with adherence to HIV treatment and the worst health status.

Background: To explore the use of illicit drugs by people living with HIV (PLHIV) taking antiretroviral therapy (ART) and their relationship with variables relevant to the management of HIV infection, such as knowledge and beliefs about drug-drug interactions (DDIs), ART adherence, quality of life (QoL), and use of health-care resources. Methods: 21 PLHIV in Spain who concomitantly took illicit drugs and ART participated in this qualitative study. Eight experts collaborated in the design of the semi-structured interview guide which explored the following topics: illicit drug use, knowledge and beliefs about DDIs and their impact on ART adherence, the effects of using illicit drugs on health, QoL, and use of health-care resources. Four of those experts, who were PLHIV and members of the executive boards of non-government organizations (NGOs) from four Spanish regions, recruited the participants through their NGOs and carried out the face-to-face interviews. Content analysis of the qualitative data was conducted with the support of the MAXQDA 12 program. Results: Participants were mainly men (85.7%) and only 14.3% of them were heterosexual. Content analysis showed that the most frequently consumed illicit drugs were poppers, cocaine, and cannabis. Participants were polydrug users and this was, in many cases, prior to HIV diagnosis. Most participants presented theoretical potential moderate DDIs that would require monitoring. More than three quarters of them were not aware of these DDIs. Participants reported interactive toxicity beliefs that lead to intentional nonadherence behaviors. In most cases (n = 17), the participant's doctor knew about their drug use, however only six of them had had an open dialogue with their physician about it. Illicit drug use led to some health-related problems, mainly sexually transmitted infections. A positive QoL's self-perception was found among several participants that used recreational illicit drugs. Conclusions: Adequate information about DDIs and clues about how to manage ART when PLHIV are using illicit drugs could reduce the negative effects of such interactions and improve ART adherence and QoL.

Drug use implies important challenges related to HIV management, particularly due to an increased risk of potential interactions between antiretroviral therapy (ART) and illicit drugs (pDDIs). This study analyses the prevalence and severity of pDDIs among people living with HIV (PLHIV). It also explores their awareness of pDDIs and their beliefs about the toxicity that they may cause, as well as the impact of pDDIs on selected health variables. We conducted an on-line cross-sectional survey across 33 Spanish hospitals and NGOs to collect demographics and clinical data. pDDIs were checked against the Interaction Checker developed by Liverpool University. The sample of the present study was composed of 694 PLHIV who used illicit drugs. They represented 49.5% of the 1,401 PLHIV that participated in the survey. After excluding 38 participants due to lack of information on their ART or illicit drug use, 335 (51.1%) participants consuming drugs presented with some potentially significant pDDIs between their ART and illicit drugs, with a mean of 2.1±1.7 (1–10) pDDIs per patient. The drugs most frequently involved in pDDIs were cocaine, cannabis, MDMA and nitrates ("poppers"). The prevalence of pDDIs across ART regimens was: protease inhibitors (41.7%); integrase inhibitor-boosted regimens (32.1%), and non-nucleoside reverse transcriptase inhibitors (26.3%). An awareness of pDDIs and beliefs about their potential toxicity correlated positively with intentional non-adherence (p<0.0001). Participants with pDDIs exhibited a higher prevalence of intentional non-adherence (2.19±1.04 vs. 1.93±0.94; p = 0.001). The presence of pDDIs was not associated with poorer results in the clinical variables analysed. A significant proportion of PLHIV who use drugs experience pDDIs, thereby requiring close monitoring. pDDIs should be considered in the clinical management of HIV patients. Adequate information about pDDIs and indicators about how to manage ART when PLHIV use drugs could improve ART non-adherence.