Crystal Meth and HIV/AIDS: The Perfect Storm?
Crystal Meth and HIV/AIDS: The Perfect Storm?
Crystal methamphetamine (CM) is an extremely addictive stimulant that increases sexual arousal while reducing inhibition and judgment. Its use is associated with a range of high-risk sexual behaviors that increase the likelihood of acquiring or transmitting HIV. Given the relatively high prevalence of CM use among people living with HIV and among men who have sex with men (MSM), there is great concern that this drug is fueling the HIV epidemic. Equally worrisome are the effects that CM use can have on the prognosis and overall health of HIV-infected patients.
Known by various street names (most commonly, “ice” and “glass”), CM can be smoked, snorted, injected, swallowed, or inserted into the rectum. Compared with other illegal drugs, CM is inexpensive, readily available, and provides a stronger, longer-lasting “high” (8–24 hours).1 Prevalence of use in the U.S. is difficult to pinpoint, but estimates of past-year use from national cross-sectional surveys range from 1.5% to 2.8% among young adults.2 Estimates of past-year use are even higher among MSM — 9.7%, according to one San Francisco study (ACC Sep 28 2005)3 — in part because the drug is now deeply embedded in the MSM “circuit party”culture.4
Commonly cited reasons for using CM, aside from peer pressure, are increased sexual sensitization, mood enhancement, and disinhibition. However, the drug is also used to provide an escape from stress, depression, alienation, and loneliness, all of which are common among people living with HIV. Furthermore, many HIV-infected MSM report using CM as a way to deal with their illness or with homophobia or prejudice.4,5 Consequently, CM use is highly prevalent among people living with HIV. In a San Francisco study, 19% to 39% of HIV-infected people reported using CM during the previous year.6 This high prevalence is alarming because CM use can increase the risk for HIV transmission and also contribute to poorer health outcomes in HIV-infected users.
Methamphetamine Use and HIV Transmission
CM use increases the risk for HIV transmission and acquisition in a number of ways.
First, the drug lowers sexual inhibitions, impairs judgment, and provides the necessary energy and confidence to engage in sexual activity for long periods of time. As a result, methamphetamine users are more likely than nonusers to engage in unprotected anal sex and to have sex with injection drug users, HIV-positive partners, and those of unknown HIV status; they also tend to report a greater number of sex partners and to have a history of other sexually transmitted diseases (STDs).3,7,8
Second, CM use is a well-documented cause of erectile dysfunction, which can lead users to engage in even higher-risk sexual activities. For example, users who cannot sustain an erection may switch to receptive anal sex (“bottoming”), which carries a higher risk of HIV acquisition than does insertive anal sex. Alternatively, users may take erectile-dysfunction drugs, and the combination of these with CM can lead to longer, more-aggressive periods of sex, potentially resulting in condom breaks or mucosal tears, which can cause bleeding and increased risk of HIV transmission.
Third, CM causes mucosal dryness, which increases the risk for tissue tears. Additional damage to rectal tissues can occur when CM is inserted into the rectum (“keistering,” “booty bumping”).
Finally, when CM is injected, needle sharing can greatly enhance transmission of HIV and hepatitis viruses.
Numerous cross-sectional studies have demonstrated an association between CM use and increased risk for HIV infection, but only a few studies have prospectively assessed seroincidence. In the largest of these, the Multicenter AIDS Cohort Study, the relative risk for HIV seroconversion was 1.5 among CM users compared with nonusers and was even higher (3.1) among men who used both methamphetamine and poppers (ACC Apr 13 2007).9
Methamphetamine Use and Progression of HIV Disease
In addition to facilitating HIV transmission, CM use is associated with detrimental behavior changes that can affect the prognosis and overall health of people living with HIV. For instance, current methamphetamine use decreases adherence to HIV treatment and medical follow-up.10 Frequent CM use has also been associated with increased risk for antiretroviral resistance, particularly to NNRTIs, with the obvious implications for treatment and transmission risk.11 For example, CM use is thought to have contributed to the acquisition of triple-class–resistant virus by the New York City patient described in 2005 (ACC Sep 1 2006).12 In addition, some patients use CM to treat HIV-associated symptoms, such as fatigue, instead of seeing a physician. Such self-medication may lead to underdiagnosis and undertreatment of HIV and to important complications such as anemia and hypogonadism.5,10
CM use may also influence progression and complications of HIV disease more directly. For example, animal studies have shown that CM can impair the immune system13 and increase HIV replication,14 and human studies suggests that it can accelerate the progress of HIV-related dementia.15
Other Consequences of Methamphetamine Use
Other consequences of CM use that are particularly harmful to HIV-infected patients include deterioration of the teeth and gums (a result of dry mouth and grinding of the teeth), reduced appetite, poor eating habits, and weight loss. Furthermore, many users “crash” after using CM for several days straight and are left with little energy and the very feelings they were trying to avoid — depression and isolation.
Other adverse effects of CM use include intense cravings for CM when not taking it; tachyphylaxis; increased risk for heart attack and stroke (because of increases in blood pressure, heart rate, and body temperature); impaired memory, reasoning, and ability to process information; and psychological problems, such as depression, psychosis, aggressive behavior, hallucinations, and paranoia. Chronic use can also cause skin lesions and damage the cardiovascular system, lungs, liver, muscles, and nerve cells in the brain.
Preventing and Treating Methamphetamine Addiction
Prevention of methamphetamine use is hampered by a relative paucity of epidemiologic data that would enable us to assess the magnitude of the current problem adequately and to evaluate the efficacy of various interventions. Despite federal efforts to restrict pseudoepinephrine imports and a nationwide decline in small methamphetamine laboratories, the drug continues to be widely available. A report from the National Drug Intelligence Center suggests that Mexican drug traders have relocated their labs from the U.S. to Mexico and have expanded distribution to the midwestern and eastern U.S., underscoring the difficulties of drug enforcement in the era of global trade.18 Developing methamphetamine prevention “task forces” (involving community members and representatives from at-risk groups, STD treatment centers, health departments, and law enforcement) is a reasonable approach, despite a lack of efficacy data.19 Educational campaigns should be tailored to specific target populations, and care should be taken to help ensure that such campaigns do not increase cravings in CM-addicted patients.20
Given the high prevalence and dire consequences of CM use among HIV-infected patients, clinicians should be sure to ask patients about past or current use. Drug testing is recommended for all patients who have a history of, or are suspected of, using CM.
Few data are available to recommend any one method of methamphetamine treatment over another.21 Cognitive behavior-based interventions (Matrix Model), 12-step programs, drug testing, and contingency management interventions have been used by different treatment centers, with varying degrees of success. Nevertheless, treatment of CM addiction can be successful in decreasing risky sexual behaviors and should be an integral part of any HIV prevention effort.21,22
All current data underscore the potential of methamphetamine to substantially worsen the current HIV epidemic, with some studies indicating that this potential is already being realized. Methamphetamine use is an important public health problem and is associated with risky sexual behavior; increased rates of transmission of HIV, other STDs, and hepatitis; serious adverse events; and poor adherence to antiretroviral treatment. Prevention efforts not only must encompass traditional education and awareness campaigns but also will require local, national, and international policy changes, including allocation of appropriate resources and funding. Comparative trials of different treatment approaches are needed, as are better evidence-based protocols for treatment.