The Dangers of Mixing Alcohol With Other Drugs

What Is Polysubstance Use?

Polysubstance use refers to the use of two or more substances at the same time or within a short period.(1) Examples of polysubstance use include using alcohol and prescription opioids or using cocaine and heroin together (speedballing).(1) This can happen intentionally or unintentionally, but it is never safe even when done on purpose. Mixing multiple drugs or mixing drugs and alcohol can make the effects of each substance stronger and more unpredictable than using them alone.(1)

Why Do People Use Multiple Substances?

People use multiple substances for different reasons. While polysubstance use is sometimes unintentional, people may intentionally combine drugs or alcohol to:(2)

• Change or heighten the effects of a substance.
• Compensate for the effects of a substance by taking another substance.
• Prevent or lessen withdrawal symptoms.
• Escape reality, sometimes due to life circumstances or trauma.
• Feel the effects of a substance when their primary drug of choice is unavailable.

Unintentional polysubstance use can happen when drugs from illegal sources are mixed (or laced) with other substances, such as fentanyl, without the person’s knowledge. It can also occur if someone’s alcoholic drink is spiked with an illicit drug.(1) Regardless of how a person begins using multiple substances, stopping can be challenging once a pattern of use develops.(2)

Polysubstance Use Statistics

Individuals who use one substance often use another.(2) According to data from the Substance Abuse and Mental Health Services Administration (SAMHSA), of the people who used methamphetamine in the past year, 68% also used marijuana, 44% used opioids, 32% used cocaine, and 13% reported heavy past month alcohol use.(2) Additional studies on polysubstance use show:

• 81% of people who use opioids also report using other substances.(3)
• 74%-80% of people who use cocaine or amphetamines report regularly using other substances.(4)
• 40% of deaths involving illegally manufactured fentanyl (IMF) in 2020 also involved stimulants.(5)

Having a substance use disorder (SUD), the clinical term for addiction, increases a person’s risk of developing an addiction to another substance.(4) According to the 2023 National Survey on Drug Use and Health (NSDUH), among the 48.5 million people with a past-year SUD, 7.5 million people had both an alcohol use disorder (AUD) and a co-occurring SUD.(6)

Dangers of Polysubstance Use

There are many dangers of mixing drugs. Polysubstance can cause a range of adverse health effects depending on the combination of substances involved.(2) Potential adverse health effects may include:(2)

• Brain damage.
• Psychiatric illnesses (e.g., psychosis).
• Seizures.
• Respiratory failure.
• Heart issues.
• Liver damage or liver failure.
• Bleeding in the stomach.
• Heatstroke.
• Coma.

Polysubstance Use & Overdose

Overdose occurs when a person ingests enough of a substance to cause serious or life-threatening effects. The risk of overdose increases significantly with polysubstance use.(2) Nearly 250 deaths occur every day in the U.S. due to substance misuse; nearly 50% of overdose deaths in 2022 involved multiple drugs.(1)

Overdose becomes easier when taking multiple substances because the effects of one substance may mask or enhance the effects of another. If a person does not feel the masked effects, it can be easy to misjudge how much of a drug they have taken.(1)

Dangers of Specific Substance Combinations

Mixing alcohol with other drugs might be a common occurrence for those who do both regularly, but most people don’t realize how dangerous this practice is. Whether combined with prescription medications, over-the-counter remedies, or recreational drugs, alcohol can amplify or interfere with the effects of these substances, setting the stage for dangerous reactions. And over time, using any combination of substances can damage your physical, mental, and emotional health. Understanding the risks involved is the first step toward staying safe.

Here’s what you should know about mixing alcohol with other substances:

What Happens When You Combine Alcohol With Drugs?

Mixing drugs with alcohol can be risky because it creates interactions that are hard to predict. Sometimes, alcohol makes a drug more powerful; other times, it weakens the effects. Either way, these combinations can cause serious health issues like heart problems, liver damage, or even overdose. The CDC warns:

If you drink alcohol while using other drugs, the effects may be stronger and more deadly than using either one alone…It can be dangerous to use two or more drugs at the same time, or within a short time of each other.

Dangers of Mixing Alcohol and Benzodiazepines

Benzodiazepines are prescription medications used for specific types of anxiety, seizures, and sleep disorders. They have an inhibitory effect on the nervous system and interact with the same neurotransmitters as alcohol, resulting in muscle relaxation and sedation.(7) Combining the two can lead to dangerously slowed reaction times, excessive drowsiness, lowered inhibitions, and dramatically decreased breathing and heart rate, which may be fatal.(7)

Dangers of Mixing Alcohol and Cocaine

Taking cocaine and alcohol together can produce a dangerous chemical called cocaethylene. This is a psychoactive metabolite of cocaine that is only formed when both cocaine and alcohol are concurrently present in the liver.(8) Cocaethylene has similar properties to cocaine but takes longer for the body to process so a person may be affected by it for a longer period and have an increased risk of sudden cardiac complications.(8) The two substances are often used together but the combination can result in several adverse health effects including cardiovascular and respiratory issues.(2)

Dangers of Mixing Alcohol and Opioids

The opioid class of drugs includes heroin and prescription opioids like oxycodone.(7) Opioids are a class of depressants and when taken with alcohol can increase the depressant effects of alcohol on both the brain and the body. Combining opioids with alcohol can cause respiratory depression, increasing the risk of a potentially fatal overdose.(9)

Dangers of Mixing Alcohol and Prescription Stimulants

Prescription stimulants include medications for ADHD, but when combined with alcohol, can be dangerous.(10) Prescription stimulants can prolong the initial stimulatory effects of alcohol, delaying alcohol’s sedating effects that would normally lead to drinking cessation.(10) Because combining the two can mask the depressant effects of alcohol, this increases the risk of alcohol overdose.(7)

Dangers of Mixing Benzodiazepines and Opioids

Both benzodiazepines and opioids cause central nervous system (CNS) depression; combining the two increases the risk of sedation and suppressed breathing, which can lead to a fatal overdose.(11) In 2021, almost 14% of overdose deaths involving opioids also involved benzodiazepines.(11)

Dangers of Mixing Benzodiazepines and Cocaine

Overdose deaths from mixing cocaine and opioids have been increasing, according to data from the 2017-2019 National Survey on Drug Use and Health (NSDUH).(12) Whether combined intentionally or due to fentanyl contamination, together these drugs increase the risk of overdose, which can be fatal.(12)

Polysubstance Use & Addiction

People who use one substance often use another, which can put them at greater risk of developing a substance use disorder (SUD), also referred to as addiction.(2) An SUD is a condition in which a person compulsively uses a substance despite the physical, psychological, and social problems use causes.(2)

Many people discover that once they begin using multiple substances, it is difficult to stop.(2) Once a single SUD develops, a person is at an increased risk of developing dependence on additional substances.(4)

Treatment for Polysubstance Use

If you or a loved one are struggling with polysubstance use, know that treatment is available, and can help address the use of multiple substances.

Treating polysubstance use can be complex and requires a comprehensive approach that addresses the use of multiple substances as well as potential withdrawal symptoms from multiple substances.(2) Many individuals who struggle with polysubstance use also have medical, psychiatric, and social needs that must be considered.(2) Effective treatment for polysubstance use is individualized and balances these challenges while providing integrated support.(2)

Treatment Settings for Polysubstance Use

Treatment for polysubstance use may take place in several settings as a person progresses in recovery. Treatment settings include:

• Medical detox: These programs provide medically supervised withdrawal management to help individuals become medically stable.(13) Medical detox is important as polysubstance abuse can lead to more complex withdrawal symptoms. These programs can help manage these symptoms, provide support, and help people remain as comfortable and safe as possible before ideally continuing to a formal treatment program.(2)
• Inpatient/residential addiction treatment: These programs may take place in hospital or residential settings, and provide care and support throughout treatment, which may range from a few weeks to a year or longer.(13)
• Outpatient addiction treatment programs: These programs take place at a program site and allow individuals to live at home. Outpatient programs vary in intensity and length and can offer individuals more flexibility.(13)
• Intensive outpatient addiction treatment programs: These are a more supportive type of outpatient program that offers 9-20 hours of weekly treatment.(13)
• Partial hospitalization rehab programs: These highly supportive outpatient programs offer 4-8 hours of daily treatment.(13)
• Aftercare programs: Aftercare, or continuing care, involves ongoing recovery efforts after completing a formal treatment program. This may include mutual aid groups, sober living options, recovery coaches, and more.(14)

FAQs About Polysubstance Use

Q: What is polysubstance use? 

A: Polysubstance use means taking two or more substances at the same time or within a short period. This may include mixing alcohol with prescription medications, combining stimulants and opioids, or unknowingly using drugs laced with other substances.

Q: Why do people combine substances? 

A: Some people mix drugs to heighten effects, reduce withdrawal symptoms, or compensate for one drug’s impact with another. Others may use multiple substances because their drug of choice is unavailable. Polysubstance use can also be unintentional, such as when illicit drugs are contaminated with fentanyl.

Q: What are the risks of polysubstance use? 

A: Combining substances increases the chance of overdose, organ damage, seizures, respiratory failure, and psychiatric symptoms. In 2022, nearly half of U.S. overdose deaths involved more than one drug. Even mixing alcohol with common medications like Tylenol can cause serious harm.

Q: Which drug combinations are especially dangerous? 

A: Alcohol with benzodiazepines, opioids, or stimulants is particularly risky because of unpredictable and potentially fatal effects. Mixing opioids with benzodiazepines or cocaine also significantly increases the chance of overdose and respiratory depression.

Q: How is polysubstance use treated? 

A: Treatment usually begins with medical detox to manage complex withdrawal symptoms safely. From there, patients may enter inpatient or outpatient rehab, intensive outpatient programs, or partial hospitalization. Aftercare, such as sober living, peer support, and recovery coaching, helps sustain long-term recovery.

Ready to find support?

Mixing substances can be unpredictable and dangerous, but treatment can help you regain control. Explore treatment programs near you to connect with personalized care and evidence-based recovery options.

Sources

1. Centers for Disease Control and Prevention. (2024, April 2). Polysubstance use facts.
2. Substance Abuse and Mental Health Services Administration (SAMHSA). (2021). Treating concurrent substance use among adults. SAMHSA Publication No. PEP21-06-02-002. Rockville, MD: National Mental Health and Substance Use Policy Laboratory. Substance Abuse and Mental Health Services Administration, 2021.
3. Bobashev, G.B., & Warren, L.K. (2022). National polydrug use patterns among people who misuse prescription opioids and people who use heroin. Results from the National Household Survey on Drug Use and Health. Drug and Alcohol Dependence. 238, 109553.
4. Crummy, E.A., O’Neal, T.J., Baskin, B.M., & Ferguson, S.M. (2020). One is not enough: understanding and modeling polysubstance use. Frontiers in Neuroscience. 14, 569.
5. Centers for Disease Control and Prevention. (2024, May 8). Polysubstance overdose.
6. Substance Abuse and Mental Health Services Administration. (2024). Key substance use and mental health indicators in the United States: Results from the 2023 National Survey on Drug Use and Health (HHS Publication No. PEP24-07-021, NSDUH Series H-59). Center for Behavioral Health Statistics and Quality, Substance Abuse and Mental Health Services Administration. https://www.samhsa.gov/data/report/2023-nsduh-annual-national-report
7. National Institute on Drug Abuse. (2023, September 19). Commonly used drugs charts.
8. Pergolizzi, J., Breve, F., Magnusson, P., LeQuang, J.K., & Varrassi, G. (2022). Cocaethylene: When cocaine and alcohol are taken together. Cureus. 14(2), e22498.
9. National Institute on Alcohol Abuse and Alcoholism. (2022). Alcohol-medication interactions: Potentially dangerous mixes.
10. Egan, K.L., Reboussin, B.A., Blocker, J.N., Wolfson, M.W., & Sutfin, E.L. (2013). Simultaneous use of non-medical ADHD prescription stimulants and alcohol among undergraduate students. Drug and Alcohol Dependence. 131(1-2), 71-77.
11. National Institute on Drug Abuse. (2022). Benzodiazepines and opioids.
12. Liu, X., & Singer, M.E. (2023). Intentional use of both opioids and cocaine in the United States. Preventive Medicine Reports. 33,102227.
13. Center for Substance Abuse Treatment. (2014). What is substance abuse treatment? A booklet for families. HHS Publication No. (SMA) 14-4126. Rockville, MD: Substance Abuse and Mental Health Services Administration.
14. U.S. Department of Health and Human Services (HHS), Office of the Surgeon General. (2016, November). Facing addiction in America: The surgeon general’s report on alcohol, drugs, and health. Washington, DC: HHS, November 2016.