How Substance Abuse Increases the Risks of Infectious Diseases
Why Drug Use Can Lead to an Infectious Disease:
The chronic use of alcohol and nearly every drug of abuse taxes the system of an individual and potentially results in compromised immune system functioning. The use of most drugs of abuse, including alcohol, leads to the suppression of the ability of the immune system to fight off infection. Individuals who binge or use extremely high amounts of drugs and alcohol also weaken the immune system by exhausting themselves. The major drugs that affect the immune system are discussed below.
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What is the Immune System?
The immune system is comprised of a number of tissues in the body that fight infection. Conditions that compromise the immune system can result in an individual being more susceptible to contracting an infectious disease. Leukocytes, or white blood cells, are important cells of the immune system that are produced and stored in many areas, including the spleen, lymphatic tissues, and bone marrow.
Leukocytes circulate throughout the body and monitor for substances that need to be eliminated from the body. There are two basic types of leukocytes: Phagocytes attack and grind up invaders, and lymphocytes allow the system to recognize previous invaders and then help destroy them. There are two types of lymphocytes: B lymphocytes and T lymphocytes.
- The National Institutes of Health has several informative websites and publications regarding how substance use disorders are associated with decreased immune system functioning.
- Readers interested in more technical information can read a report from the National Institute of Alcohol Abuse and Alcoholism (a subsidiary of the National Institute of Drug Abuse).
- Individuals interested in even more technical information may wish to pick up the publication Neuroimmune Signaling in Drug Actions and Addictions, a volume of the International Review of Neurobiology.
While research suggests that light to moderate alcohol use may strengthen the immune system in some individuals, it has long been observed by physicians that individuals who excessively drink alcohol have higher rates of infectious illnesses, such as pneumonia, as well as the development of liver damage. Chronic alcohol abuse results in immunodeficiency and liver damage that may also be partly triggered by alcohol-induced autoimmunity where the individual’s immune system begins to attack its own body’s tissues.
Chronic alcoholics are susceptible to such infectious diseases as:
- Hepatitis B and C
Research indicates a clear relationship between chronic abuse of tobacco products and decreased immune system functioning.
Chronic tobacco abuse is associated with:
- Decreased antibody formation in both animals and humans
- Decreased lymphocyte proliferation in both animals and humans
- Decreased availability of antioxidants in heavy smokers
- Increased infection susceptibility to nearly every bacterial and viral infection tested
- Extreme susceptibility to respiratory infections as would be expected
Opioid drugs all originate from substances derived from the poppy plant. Their primary medicinal use is to control chronic pain. As a side effect, many of these drugs produce significant feelings of euphoria and are high potential candidates for abuse and the development of physical dependence.
It has long been established that chronic use of opioid drugs, such as morphine, heroin, Vicodin, OxyContin, tramadol, etc., results in hindering the immune system’s ability to fight off both viruses and bacteria invaders. Research suggests that morphine, the prototypical opioid drug, suppresses the activity of the different types of white blood cells that are important in fighting off infections. This suggests that individuals who chronically abuse opioid drugs are susceptible to any number of infectious diseases and will most likely experience respiratory infections like colds and influenza (due to a combination of the drugs inhibiting respiration and suppressing the immune system), cardiovascular infections, and issues with the liver and kidneys.
It is also probably safe to assume that not all opioid drugs have similar effects on the immune system; however, the specific effects on immune system functioning of each opioid drug are not well known. Currently, it is probably safest to assume that opioid drugs in general suppress immune system functioning. When taken in large doses over lengthy periods of time, drugs that combine opioids with medications like acetaminophen, such as tramadol, can suppress the immune system and result in liver toxicity, which further suppresses the ability to fight infection.
There are a number of animal models that suggest that chronic use of cannabis products may be associated with decreased immune system functioning; however, these findings are less clear in adult humans. However, it is safe to conclude that children and adolescents who use cannabis products regularly most likely do experience suppressed immune system functioning.
As with other drugs, chronic use of cocaine affects the immune system and leads to an increased susceptibility to develop infections. One interesting aspect of cocaine abuse is its suppression of the thymus gland that produces T lymphocytes, which attack foreign cells. Chronic cocaine abuse appears to hinder the ability of certain groups of the cells to develop and also increases the rate of the number of the cells that undergo programmed cell death prematurely (apoptosis). The more cocaine one uses, the more cells die off.
Issues with Injecting Drugs and Other Risky Behaviors
While the majority of research indicates that chronic abuse of any class of drugs results in decreased immune system functioning and an increased susceptibility to develop a number of different issues, there are various other methods by which individuals with substance use disorders increase their susceptibility to the risk of contracting infections.
Drugs that are commonly injected include morphine, heroin, methamphetamine, and cocaine. Injection of these drugs and sharing needles accounts for a significant proportion of cases of HIV per year and is also a major factor in the spread of hepatitis C, which is a serious and potentially fatal disease of the liver. Obviously, needle sharing as a result of drug abuse is a major factor in the spread of these serious infectious diseases.
In addition, the use of many of these drugs increases the likelihood that individuals will engage in risky behaviors, such as unprotected sex. This can result in a number of sexually transmitted diseases, the spread of HIV, and the spread of diseases like hepatitis B and C.
Chronic drug abusers engage in a number of other behaviors that open them up to the risk of developing infection. Oftentimes, these individuals neglect aspects of their personal hygiene and nutrition. They often engage in bingeing behaviors that result in a number of different stresses on bodily systems and also lead to increased susceptibility to infections and diseases. Individuals who abuse multiple drugs multiply their risk factors significantly.
Individuals with chronic substance use disorders very often have comorbid (co-occurring) psychological or psychiatric disorders, such as depression, anxiety disorders, and personality disorders. People with these mental health issues are also known to be particularly susceptible to infections and diseases of all types. Thus, individuals with substance use disorders typically have increased chances of catching an infectious disease through a number of different pathways.