How Can Doctors Track Risky Drinking IV Drug Users?
Excessive consumption of alcohol can significantly increase the health risks associated with intravenous (IV) drug intake and other forms of injection drug use. However, public health officials and doctors sometimes encounter difficulty when trying to accurately track IV/injection drug users’ drinking habits. In a study published in 2014 in the journal Alcohol and Alcoholism, researchers from UC San Francisco assessed the usefulness of an indicator or biomarker for risky drinking behavior, called phosphatidylethanol, in helping doctors record the amount of alcohol consumed by injection/IV drug users.
Alcohol and IV/Injection Drug Use
Injection drug users introduce at least one of a range of substances into a vein, into muscle tissue or beneath their skin. Commonly injected substances include heroin, crushed opioid medications, cocaine, methamphetamine and crushed stimulant medications. In addition to the direct harmful impact of rapidly exposing the brain to powerful drugs, participation in this form of drug abuse exposes the user to a range of contaminants that can contribute additional drug effects or serious damage to the cardiovascular system (heart and blood vessels). Injection drug use is also one of the main pathways for the transmission of potentially lethal infectious agents such as HIV (the human immunodeficiency virus) and the hepatitis C virus. In addition, this form of drug abuse creates risks for a range of highly damaging localized tissue infections.
Consumption of alcohol can contribute to injection/IV drug users’ already prominent risks for exposure to HIV and other infectious, lethal microorganisms. This is especially true for people who binge on alcohol (drink enough to get legally drunk within a couple of hours). These individuals have steeply heightened chances of acting impulsively and exposing themselves to infection through participation in unprotected sex and/or sex with more than one partner in a short span of time.
Like other substance abusers, injection/IV drug users do not necessarily readily admit their involvement in what is essentially illegal behavior. This means that doctors often need to follow up their suspicions about drug use without any help from their patients. The reluctance to talk about drug-using behavior may also extend to other substances consumed by injection/IV drug users.
Doctors and researchers use the term biomarker to refer to detectable indications of biological change in the body of a person who has an illness or has otherwise been exposed to something that alters the body’s function in some important way. Phosphatidylethanol is a biomarker that appears in the blood of a person who regularly participates in binge drinking or any other form of excessive alcohol consumption. It typically remains for 14 to 21 days if another drinking episode does not occur. Phosphatidylethanol has potentially unique usefulness as a biomarker for problem drinking. For instance, it does not appear in significant amounts in people who only drink occasionally; in addition, it does not appear in the aftermath of the routine use of antiseptic hand sanitizers, mouthwash or other alcohol-containing household products not usually associated with drinking.
Tracking Alcohol Use
In the study published in Alcohol and Alcoholism, the researchers used a long-term project involving young-adult injection/IV drug abusers to test the value of phosphatidylethanol as a biomarker for the alcohol consumption habits of people who inject drugs. They conducted this project, in part, because injection/IV drug abusers may not accurately self-report their drinking behaviors. In addition, other factors may interfere with researchers’ ability to record common patterns of alcohol intake in this substance-using population.
All of the study’s participants were asked to report their involvement in drinking. The researchers used dried blood collected from the bodies of the participants to test for the presence of phosphatidylethanol. After comparing the self-reports of drinking behavior to the results of the phosphatidylethanol testing, the researchers concluded that the subjective reports of drinking matched up fairly well with the objective test results. Specifically, they concluded that the phosphatidylethanol levels in the participants closely reflected the self-reported number of days on which alcohol intake occurred over a month-long period of time. Crucially, phosphatidylethanol testing was also highly accurate in identifying the injection/IV drug users in the project who did not consume alcohol. In line with these findings, the study’s authors believe that phosphatidylethanol levels may be an important and reliable biomarker for alcohol use in injection/IV drug-using populations.