Access to antiretroviral therapy in HIV-infected injection drug users

In the past 5 years we have experienced a dramatic decrease in HIV disease progression and related mortality in developed countries, mainly as a result of the existence of highly active antiretroviral therapy (HAART) and the rapid access to it in this setting [1–3]. Nevertheless, not all the HIV-infected population has the same access to antiretroviral therapy, and it has been stated that ethnic minorities, women, injecting drug users and individuals with low income and the absence of insurance have more difficulties in obtaining the correct treatment, even in developed countries with universal and free access to sanitary care and therapy [4,5]. Many times, this reflects the limited accessibility of these individuals to sanitary care, whereas on other occasions it is a consequence of the concerns of clinicians about the possible poor adherence of this marginal population to antiretroviral therapy [6]. In this case, it has to be remembered that factors such as sex, race, socioeconomic status, educational level, and a past history of drug use do not reliably predict poor adherence, in the same way that higher socioeconomic status and educational levels and the lack of a history of drug abuse do not predict good adherence [7]. Regarding only the population of HIV-positive intravenous drug users, Celentano et al.[8] demonstrated in their excellent research that as many as 32% of participants in their prospectively followed cohort remained treatment-naive 3.5 years after reaching a CD4 cell count below 500/μl. At this time-point, 59% had a history of receiving HAART, which represents an encouraging increase when compared with the 14% from a previous analysis of the same group [9]. Most of them were previously on zidovudine monotherapy or dual combination therapy, and as many as 34% remained on this suboptimal therapy, which is an unacceptable number of patients, taking into account that this modality of treatment is unable to suppress viral replication, and can lead to drug resistance and the limitation of future options [10]. Of interest was the fact that, in their cohort, initiating HAART was independently associated with methadone treatment among men, not using drugs, and having a regular source of care, among other factors. We previously demonstrated how HIV-infected injecting drug users can benefit from a methadone maintaining programme [11], improving in this way the follow-up, and increasing the access and adherence to therapy and prophylaxis, resulting in better immunological and clinical outcomes. In another recent report from our group [12], and in contrast to previous reports [13,14], we have shown that HIV-infected patients on stable methadone maintenance programmes are able to reach similar outcomes to the overall antiretroviral-naive population after 12 months of potent protease inhibitor-based HAART. In the same way as our results, a recent study [15] demonstrated that in HIV-positive drug users, hospitalization rates were lower for those with both regular medical and drug abuse care. A remarkable finding in our cohort was the significantly longer time from AIDS diagnosis to the moment of initiation of antiretroviral therapy in methadone-receiving patients in comparison with the overall population (27 versus 2 months, P = 0.0001), reflecting a higher rate of progression of HIV infection before enrolment in methadone maintenance programmes, mainly as a result of their lifestyle, which did not allow them to begin on therapy, or to the reluctance of physicians because of concerns about compliance [12]. A separate mention needs to be made about the apparent lack of efficacy of methadone maintenance programmes in women in the study by Celentano et al.[8]. We have not found this sex difference between our patients, which probably reflects the fact that in some settings women have other factors, related more to the drug abusers lifestyle than to active drug use, which make it more difficult for them to access therapy and follow-up [5]. In summary, taking into account the findings of Celentano et al.[8], recognizing drug abuse treatment as a prognostic factor that facilitates access to HIV infection therapy, and our own results and those of others [11,12,15], which showed good outcomes for methadone-receiving antiretroviral-treated patients, we must emphasize the utility of drug substitution programmes, such as methadone maintenance programmes, as an efficient tool to improve the care and outcome of HIV-infected injecting drug users.