Unlike doctors in the early days of HIV\/AIDS, today's doctors have potent medical tools to limit the spread of HIV (human immunodeficiency virus) and suspend the progression toward AIDS (acquired immune deficiency syndrome). The frontline tool used for this purpose, known as antiretroviral therapy or ART, involves the simultaneous use of multiple medications designed to disrupt HIV's normal life cycle. But for ART to do its job, patients must follow a fairly complicated medication routine. HIV-positive people who consume alcohol - even at relatively moderate levels - have a decreased tendency to adhere to the guidelines of ART treatment, and therefore have increased risks for significant HIV disease progression. ART Basics Antiretroviral therapy gets its name because it involves the use of drugs that target HIV, a viral species that belongs to a larger group of viruses known as retroviruses. There are dozens of antiretroviral drugs on the market, each of which falls into one of three main medication categories: nucleoside\/nucleotide transcriptase inhibitors (popularly abbreviated as NRTIs), nonnucleoside reverse transcriptase inhibitors (popularly abbreviated as NNRTIs), and protease inhibitors (popularly abbreviated as PIs). Antiretrovirals achieve their effects by targeting specific phases of HIV's normal life cycle and disrupting the virus's ability to reproduce copies of itself. Initially, doctors gave their patients doses of single antiretroviral drugs. However, they eventually noticed that certain numbers of HIV copies in any given person will adapt to the presence of a single antiretroviral medication, avoid that medication's disruptive effects and continue reproducing. In response to this observation, doctors began simultaneously using multiple antiretroviral medications that target different phases of the HIV life cycle. The vast majority of HIV copies can't survive this multi-pronged attack on their reproductive capabilities; as a result, the use of multiple medications kills off large numbers of HIV and drastically reduces the amount of the virus in an infected individual's bloodstream. In turn, a large-scale reduction in HIV levels greatly slows the progression toward AIDS and prolongs the lives of HIV-positive people. ART Compliance In its modern, multi-medication form, ART is also known as highly active antiretroviral therapy (HAART) or combination antiretroviral therapy (CART). Although the specifics of treatment vary widely, essentially everyone who receives HAART or CART takes a minimum of three medications, at least two of which come from different drug categories (NRTIs, NNRTIs, or PIs). In order to effectively contain HIV and produce their long-term treatment benefits, these medications must be taken according to explicit instructions set forth by a prescribing physician. In fact, people receiving HAART or CART must follow their dosing instructions at least 95 percent of the time to experience the full benefits of therapy. Despite this fact, HAART and CART patients follow their treatment regimens just 40 to 90 percent of the time, according to a series of studies published in the 2000s and reviewed by the National Institute on Alcohol Abuse and Alcoholism in 2010. In some cases, patients don't properly follow their prescribed treatments because of toxic side effects associated with those treatments. In other cases, outside influences such as alcohol consumption reduce treatment compliance. Impact of Alcohol Consumption Alcohol consumption reduces patient willingness to follow medication regimens in general, not just HAART or CART regimens, the NIAA explains. In some cases, drinkers show a reduced tendency to take their medications on days when they use alcohol; in other cases, this tendency manifests on the days that follow active alcohol use. Generally speaking, in any given individual, heavier amounts of alcohol consumption are associated with a greater likelihood of skipping single or multiple medication doses. While drinkers as a whole have problems adhering to their medication routines, binge drinkers have much greater chances of skipping their medications, especially on days when they consume alcohol. Doctors and public health officials typically define binge drinking in males as consuming five or more drinks within a two-hour time period; binge drinking in females is defined as consuming four or more drinks in two hours. People typically start to reduce their compliance with their HAART and CART treatment programs when they consume two or more drinks on any given day, the authors of the 2010 NIAAA review report. Critically, the lower end of this level of alcohol consumption meets standard definitions for moderate or "safe" drinking. On average, a HAART or CART patient who drank daily but didn't participate in binge drinking would shorten his or her lifespan by roughly 8 percent. Conversely, a HAART or CART patient who participated in binge drinking every day would shorten his or her lifespan by 25 percent. While the real-world impact of drinking varies from person to person, alcohol consumption during antiretroviral therapy is clearly associated with a faster progression of HIV and an earlier death. In some cases, the effects of alcohol consumption are worsened by alcohol's ability to intensify the liver-related side effects of certain antiretroviral drugs.