Effects & Dangers of Mixing Opioids and Stimulants

Using more than one substance at a time, especially opioids and stimulants, is extremely risky.¹ This practice, known as polysubstance use, can have severe consequences.¹

This page will focus on the combined use of opioids and stimulants, including the risks associated with polysubstance use of the two, the effects they can produce both individually and together, and how to access effective treatment.

Combining Opioids and Stimulants

Illicit stimulant substances include drugs such as methamphetamine, cocaine and crack cocaine, bath salts, and khat.² Legal prescription stimulants include Adderall, Dexedrine, Concerta, and Ritalin, and are most commonly used to treat symptoms of attention-deficit/hyperactivity disorder, or ADHD, but can also be misused.²

There are opioids that are illicit and ones that are FDA-approved for the treatment of certain medical conditions. Illicit opioids include illegally manufactured fentanyl and heroin, while common prescription opioids include oxycodone, fentanyl, and hydrocodone.

Stimulants work by increasing activity in the central nervous system (CNS), while opioids work by depressing CNS activity. Each class of substances has high potential for addiction and overdose when misused. Although they each have their medical purpose, opioids and stimulants can often be misused in both their illicit and medicinal forms.

Recent data reveals that Americans struggle with addictions to opioids and stimulants: 5.7 million people with opioid use disorder and 4.3 million people with stimulant use disorder.³ A study in 2024 highlights a substantial increase in stimulant use (particularly methamphetamine) among individuals who also use opioids.⁴ In this study, past month stimulant use rose dramatically from 9% to 44% between 2015 and 2019 among heroin users.⁴

People may combine stimulants, both illicit and prescription, with various opioids, leading to extremely hazardous outcomes.⁴ For example, illicit fentanyl is a key contributor to the overdose epidemic in recent years, both on its own and in combination with other substances, like stimulants.^5,6 In numerous fatal overdoses involving stimulant and opioid combinations, fentanyl plays a central role.⁵

Dangers of Mixing Opioids and Stimulants

As previously mentioned, opioids work by depressing the central nervous system (CNS), slowing brain activity, while stimulants have the opposite effect and increase CNS activity.^1,7,8 This fundamental difference creates a dangerous and unpredictable combination, as the opposing side effects of these substances can mask each other, leading to a false sense of security and increasing the risk of overdose.¹ For example, an individual who uses opioids at the same time as using stimulants, may not feel the desired effects of opioids, and as a result may increase their opioid use or vice versa. This dangerous behavior can potentiate the risk for overdose.¹

Effects of Opioids

People can experience a variety of short- and long-term effects from opioids, regardless of whether they are illicit or prescription opioids.⁷

Potential short-term effects of opioids can include:⁷

• Euphoria.
• Dry mouth.
• Itching.
• Nausea.
• Vomiting.
• Pain relief.
• Drowsiness.
• Constipation.
• Dangerously slowed breathing and heart rate.

Long-term effects of opioids, which can sometimes vary depending on the method of use, may include:^7,9

• Collapsed veins (if injected).
• Abscesses (swollen tissue with pus).
• Constipation and stomach cramps.
• Liver or kidney disease.
• The onset of depression.
• Sleep-disordered breathing.
• An increased risk of overdose.
• An increased risk for developing addiction.
• Cardiovascular complications such as infection of the lining and valves in the heart (endocarditis), heart attack, or heart failure.

Effects of Stimulants

Stimulant misuse, regardless of whether a person uses prescription stimulants or illicit ones, can also result in a variety of short- and long-term effects.

Short-term effects of stimulants may include:⁷

• Enlarged pupils.
• Decreased appetite.
• Abdominal pain and nausea.
• Increased blood sugar.
• Increased energy and alertness.
• Restlessness.
• Anxiety, panic attacks, and/or paranoia.
• Increased body temperature, heart rate, and blood pressure.
• Cardiac complications, including heart arrhythmias, heart attack, stroke, and narrowed blood vessels.

People who chronically misuse stimulants can also suffer from a variety of long-term effects, some of which may vary by method of use.

These long-term effects may include:⁷

• Insomnia.
• Mood problems.
• Cognitive problems.
• Cardiovascular problems.
• Lung damage from smoking.
• Malnutrition due to decreased appetite and weight loss.
• Severe dental problems (specifically in those who misuse methamphetamine).
• Loss of sense of smell, nosebleeds, nasal damage, and trouble swallowing (from snorting stimulants).
• Increased likelihood of developing stimulant use disorder.

Interactions Between Opioids and Stimulants

Opioids and stimulants interactions can be unpredictable and dangerous, possibly leading to a variety of effects that may include:¹⁰

• Dehydration.
• Kidney failure.
• Cardiovascular problems, including heart failure.
• Respiratory infections, such as bronchitis.

One of the most significant interactions of all, however, is the increased risk of overdose when stimulants and opioids are combined.^4,5 For example, in the United States, fatal overdoses caused by the co-involvement of fentanyl and stimulants increased from 17,100 in 2018 to 32,200 in 2021, highlighting this very real risk.⁵

Opioid and Stimulant Addiction Treatment

With the right treatment, addiction can be treated over time. People who seek treatment may begin at varying levels of care based on where they are in their recovery journey at the time of admission, as well as their personal needs. Treatment options often include:¹¹

• , where people are professionally assisted as they undergo substance withdrawal so they can become medically stable and often continue to formal treatment.
• , where people live onsite at a rehab, receive 24/7 care and support, participate in therapy, and receive different treatments.
• , or high intensity outpatient programs (HIOPs), which are outpatient programs offering about 4-8 hours of daily treatment each week.
• , which are also supportive outpatient programs, however do not require the same time commitment as a partial hospitalization programs, but instead about 9-20 hours of treatment a week.
• , which allow people to live at home, but they will need to travel to a rehab on a set schedule to receive treatment.
• , which is a drug- and alcohol-free residence that provides structure, support, and reintegration assistance for people in recovery.
• , which refers to ongoing recovery support interventions, such as 12-Step groups or individual counseling, to help prevent relapse.

Getting Help for Opioid and Stimulant Addiction

If you or a loved one is ready to seek rehab for a substance use disorder, explore your options and reach out to a rehab center using our rehab directory tool today!