Since the relationship between drug use and AIDS was first identified, drug users have been the target of a broad range of interventions designed to prevent HIV transmission, but none have received as much scientific attention as substance abuse treatment. The data reviewed here provide strong and consistent evidence that effective treatments for drug abuse and dependence reduce the frequency of use, risk behaviors, and infections. While these findings were observed during the first 15 years of the epidemic primarily from countries with existing drug treatment systems, more recent data are able to provide evidence of these same impacts, particularly in countries with more recently established treatment programs and systems. The consistency of this relationship over time and across cultural settings is impressive and serves as a reminder that drug abuse and dependence, like other medical conditions, respond in a reliable and predictable manner when treated using evidence based approaches. We believe that the primary mechanism underlying this relationship is the ability of medication assisted treatments for opiate dependence to address the biological and behavioral components of abuse and dependence and thereby stop or reduce injections.
Importantly, there is increasing evidence of the positive effects of medication assisted treatments other than methadone. Studies of buprenorphine/naloxone and naltrexone now appear in the literature and are producing findings consistent with those of methadone treatment for those who stay in treatment. This is particularly important considering the need for multiple treatment options in communities affected by HIV and other blood borne and sexually transmitted infections.
Given the importance of effective antiretroviral treatment as an HIV prevention intervention, the recent literature significantly expands the role of effective substance abuse treatments as HIV prevention. Through participation in effective treatments, drug users have improved access to antiretroviral treatment, improved adherence to those treatments, and improved chances of sustained reductions in viral load. These studies have also provided clear evidence that current use of substances, not past diagnoses or individual characteristics, is the critical factor in adherence.
Despite the growth of the literature and continued positive findings on drug treatment as HIV prevention many important issues require additional research attention. Among these is the need for data to more clearly define the role of counseling in medication assisted treatments. While findings that drug treatment reduces risk and infection with HIV have been widely promulgated, this has in some instances promoted the mere distribution of agonist medication. While such “low demand” interventions will undoubtedly help many dependent individuals avoid withdrawal, risk behaviors and other negative consequences associated with dependence, it is not clear that this strategy is a very effective treatment for addiction.
Within treatment programs themselves, there remains much to be done to maximize their HIV prevention potential. The fact that HIV testing is performed in only a minority of treatment programs is a serious concern and in direct conflict with global prevention initiatives. The potential of directly observed treatment and contingency management strategies as a tool for improved adherence to HIV medications among methadone patients provide important direction for future research and program development.60,77,78
Given the fact that only a small portion of drug users ever enter formal treatment, research is also needed to develop and evaluate strategies for embedding effective drug treatments in non-traditional settings where risk behaviors are common and HIV infection is prevalent. Enormous opportunities exist for the delivery of health promoting drug treatment messages outside of drug treatment programs. Schools, work environments, emergency rooms, homeless programs, and primary health care settings are all viable locations for “low intensity” drug treatment interventions and could significantly expand access to drug treatment.
HIV prevention research should be more closely linked to medication development efforts. New, long acting formulations of existing medications (naltrexone and buprenorphine) offer opportunities for significant advances in HIV prevention efforts. As new medications for stimulant abuse move through safety and efficacy trials, measures of risk behavior need to be included. Vaccines for drug abuse are also in early stages of development and prevention research needs to be present. By testing the efficacy of these new products and strategies early in their development, their indication for use as prevention interventions may be accelerated.
Given the important role of heroin injection in propelling the spread of HIV via injection related risk, most of the published research has involved opiate users and their treatment. The literature is quite clear that medication assisted treatments are effective HIV prevention strategies. Unfortunately, comparably effective medication assisted treatments for cocaine and other stimulant use are not currently available. While treatment strategies that do not use medications have shown some evidence of efficacy among high risk stimulant users, the development of a safe and effective treatment medication for stimulant abuse and dependence remains a high priority.
Clearly, drug treatment programs play a critical role in controlling the spread of HIV and improving its treatment in many communities around the world. Still, the great majority of drug users do not have access to effective substance abuse treatments--even in countries considered to be more highly developed. 79
The data reviewed in this paper can help to promote policies designed to increase access to drug treatment. While important challenges remain in maximizing its impact, the scientific literature provides strong evidence of the efficacy of drug treatment as an HIV prevention strategy.