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Drug Abuse and Cardiovascular Health Risks: How Do Drugs Affect the Heart?

What Are the Dangers of Drug Use?

Both illicit and prescription drugs present many risks to individuals who misuse them. Drug abuse affects the brain in many ways that may lead to unpredictable, dangerous behaviors, social and emotional problems, and the development of addiction, also known as a substance use disorder (SUD).

In addition to the toll it takes on mental and behavioral health, drug abuse in its many forms can profoundly impact the body—damaging several organ systems and influencing a decline in general physical health. The cardiovascular system is one bodily system that can be especially affected by certain substances.

The cardiovascular system includes the heart, arteries, veins, and capillaries, which move blood around the body to supply organs and tissues with oxygen and nutrients, while removing carbon dioxide and other wastes. The side effects of misusing illicit drugs and prescription medicines can range from mild to severe and can differ depending on the type of substance used and the method of taking it.


Stimulants can be illicit or prescription drugs that have similar, often severe effects on the cardiovascular system.1 Stimulant drugs include illicit and prescription drugs, such as:2

The heart-damaging effects of these drugs are mainly because stimulants activate the sympathetic nervous system, which controls the release of adrenaline and other components of the “fight or flight” response. Even though stimulants activate sympathetic signaling through differing mechanisms, many of the effects are ultimately the same and can include:1,2

  • Increased heart rate (tachycardia).
  • Irregular heartbeat (arrhythmia).
  • Narrowed blood vessels (vasoconstriction).
  • High blood pressure (hypertension).

Together, these effects greatly increase an individual’s risk of experiencing myocardial ischemia (reduced blood flow to a portion of the heart), which can lead to myocardial infarction (the death of oxygen-starved heart muscle, known commonly as a heart attack).

Additionally, long-term abuse of stimulants can cause spasms of the heart muscle that eventually lead to tears in the arteries supplying the heart with oxygen or even the walls of the heart itself.3

Cocaine and Heart Attacks

Cocaine is one of the most widely misused stimulants in the U.S., with 1.7% of the U.S. population reporting cocaine use in 2021.4

In addition to the effects discussed above, cocaine use presents some unique cardiovascular risks. These risks are associated with premature heart attacks and other cardiovascular problems, even in people who are otherwise healthy. Cocaine has also been shown to increase the tendency of the blood to clot, which further increases an individual’s risk of blocked arteries that could lead to heart attacks.5

People who misuse this drug also frequently combine cocaine with alcohol (polysubstance use) to enhance the effects or to reduce the effects of alcohol intoxication. Unfortunately, both substances alone are capable of increasing heart rate, and the combination of the two can boost heart rate to even more dangerous levels.


Like stimulants, opioids can pose risks to people who use and misuse them. However, the effects of these drugs on the cardiovascular system are the opposite of those of stimulants. In general, opioids decrease sympathetic signaling in the body and activate the parasympathetic nervous system, which controls the “rest and digest” state of various organs and bodily systems.

This is true for both illicit and prescription opioids, including drugs such as:

Many of the effects of opioids are the opposite of those produced by stimulants, including:6

  • Dangerously slowed heart rate.
  • Slowed breathing.
  • Irregular heartbeat (arrhythmia), which can also occur with stimulant use.


The most popular street drug in the U.S., many users consider marijuana (cannabis, weed, pot) to be a safe and harmless substance. However, marijuana use can have several dangerous side effects, including an impact on the cardiovascular system.

Research continues to be done, but marijuana may have various cardiovascular effects, particularly when it is mixed with alcohol, which can include:6,7

  • Increased heart rate.
  • Increased blood pressure.
  • The potential risk of a heart attack.

In rare cases, marijuana use may be a trigger for a heart attack, especially in the first hour after use.7

Designer Drugs

Over the last decade, so-called “designer drugs” have become widely available in convenience stores and head shops around the country, as well as through the Internet. Prominent examples are synthetic cannabinoids (spice, K2, fake weed) and synthetic cathinones (bath salts).

While some—but not all—of these substances are not specifically prohibited by drug laws, none are approved for human consumption and many have dangerous cardiovascular effects.

Synthetic Marijuana

Synthetic cannabinoids like Spice have cardiovascular effects that are like those of marijuana, but many synthetic variations are more potent than marijuana and may be even more dangerous.

Synthetic Cathinones

Synthetic cathinones are mostly used as substitutes for stimulants like cocaine and MDMA. Synthetic cathinones have cardiovascular effects similar to those of these drugs, although they too are perhaps even more dangerous than traditional stimulants.

A Scottish study of patients who visited an emergency department after using the popular bath salt mephedrone (4-MMC, “meow meow”) found that 79% had a rapid heart rate and 74% had high blood pressure. Additionally, 25% of these patients complained of chest pains and 21% of heart palpitations, suggesting that this drug causes a high degree of cardiovascular distress.8

Effects of Injection Drug Use

People who inject different types of drugs can be exposed to additional risks. Regardless of the specific drug used, intravenous (IV) drug use poses many risks due to repeated injections using improperly sterilized paraphernalia. These include:

  • Scarred and/or collapsed veins.
  • Bacterial infection of the blood vessels.
  • Infections in the valves and lining of the heart.

In addition to these effects, some additives and contaminants in street drugs like heroin and cocaine may not be fully dissolved before injection. These contaminants can clog blood vessels supplying oxygen and nutrients to organs, leading to infections and tissue death in the lungs, liver, kidneys, or brain.

Get Help for Substance Abuse or Addiction Today

Many popularly misused drugs—both illegal and prescription—have negative effects on the body, and the effects on the cardiovascular system, in particular, can range from mild to fatal. The substances discussed in this article are only a partial list. Even drugs generally considered to have mild cardiovascular effects may lead to heart problems.

Unfortunately, many people may not be aware of these risks and may hide their drug use, making it difficult for physicians to properly diagnose and treat any associated health issues, should they arise. People who engage in polysubstance use may compound these health risks. Further complicating the issue is the fact that the precise effects of these combinations are often understudied and quite difficult to predict.

The cardiovascular side effects of substance misuse can be deadly and may occur without warning, even in individuals who are not habitual drug users. Those who are addicted to drugs are at even greater risk because these dangers increase when the body is exposed to substances repeatedly over a long period of time.

Addiction is treatable and may benefit from the support of a treatment team and trusted loved ones. There are many resources available if you or a loved one is struggling with drug or alcohol misuse.

To learn more about options for drug treatment, please contact the caring team at American Addiction Centers (AAC) free at . They are available 24/7 to answer your questions and help you find the right treatment for you or someone you love.

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