HIV-infected, MSM who use crystal meth are a unique population. They are more likely to have high risk sexual behaviors, STIs, and serodiscordant UAI compared to HIV-infected MSM who do not use crystal meth, and also relative to HIV-uninfected, crystal meth-using MSM. Their reasons for use may in part relate to their HIV diagnosis, whether they use crystal meth for sexual enhancement, to escape social isolation, or to feel more physically energetic. Medication adherence in this population is also notably low, which may contribute to the transmission of resistant virus that has been seen in newly infected MSM who use crystal meth. Given the lack of effective treatment options, providers may not have the tools to adequately address this issue, especially in the primary care setting.
The treatment studies, although well-designed, have failed to show a sustained impact in decreasing crystal meth use; no medications have proven effective in this population. A phase 2 clinical trial is currently underway evaluating the role of extended release naltrexone (Vivitrol®, Alkermes, Waltham, MA) in crystal meth-dependent individuals.73
Early animal models suggest that there may be a role of varenicline (Chantix®
, Pfizer, New York, NY) in the treatment of crystal meth abuse.74
Meanwhile, the role of behavioral therapies is still in question. Some studies have demonstrated the potential benefit of contingency management for the treatment of crystal meth dependence. However, key limitations of CM include failure of the intervention to adequately address participants' mental health needs or work with participants to develop relapse prevention plans postintervention. Interventions testing the efficacy of CM alongside other therapies such as CBT have proven modestly effective in reducing crystal meth dependence,61,66–68
however, these have not been routinely adopted into clinical practice due to cost75
and required infrastructure. Some studies have focused on decreasing UAI as the primary outcome. Reducing UAI is not only meaningful in reducing transmission of resistant HIV, but also has been easier to achieve in prior studies as opposed to reductions in crystal meth use.
When looking at these treatment studies it is important to recognize that many behavioral therapy trials were not exclusively in an HIV-infected MSM population.56–58,61,67,70
The HIV-infected population may have different relationships with medical providers and variable attitudes regarding adherence and healthy behaviors compared to the HIV-uninfected population. Thus, their response to behavioral counseling and treatment may be different than those that are uninfected. When focusing on HIV-infected individuals, poor health-related outcomes such as increased viral loads, increased transmission or resistant HIV, and decreased CD4 counts must be emphasized. Future studies that focus on behavioral interventions for HIV-infected individuals will need to explore these motivators in more detail.
The limitations of the current review mostly pertain to the methodological quality of the available studies. Many studies regarding risk behavior and adherence were cross-sectional or retrospective studies. Thus, causation cannot truly be determined. Furthermore, substance use, medication adherence, and sexual behaviors were often determined through self-report rather than more objective means such as toxicology screens and STI testing. Only one study used MEMS caps as a reliable marker of adherence.53
Given the sensitive nature of these behaviors, participants may have under-reported their sexual and crystal meth-using behaviors.
Finally, there is much geographic variation in patterns of crystal meth use. Many studies in this review were performed in California, although some in Seattle and other locations. As a result, it may be difficult to generalize or apply them to different geographic regions. We limited our search to English-language studies based in the United States to account for this geographic variation, which would likely have been even more prominent international studies were included.
The treatment of HIV-infected MSM who use crystal meth must remain a priority among health care providers. By reducing crystal meth use, we can have an impact on individual HIV-related outcomes, and subsequently reduce HIV transmission rates on a population level. At this time, there is no clear treatment guidance regarding the best ways to reduce crystal meth use. As such, we must continue with research efforts that develop and test novel strategies. In the short term, however, the available data suggest that we continue to focus our efforts on decreasing high-risk behaviors in this population. Furthermore, among providers, it is critical that we continue to assess our patients' substance use. Even though there are no clear treatment options, adherence, risk reduction counseling, and linkage to care should remain an important focus in caring for this vulnerable population.