Treating Polysubstance Use: When People Use More Than One Drug

Polysubstance use is the use of more than one substance, either at the same time or over the same period, such as combining an opioid with a stimulant or unknowingly taking a drug adulterated with another. It has become the norm rather than the exception in the current drug supply, and it complicates treatment because a program built around a single substance often leaves the other exposures untreated. Mobile programs help by delivering integrated care: one team that screens for multiple substances, offers medication for opioid use disorder, provides behavioral treatment for stimulant use, addresses wounds and overdose risk, and keeps people connected over time. The value of a mobile model here is that it meets people who use several drugs where they are and treats the whole picture in one place.

The stakes are high because mixing substances raises the risk of a fatal overdose and because the supply itself is unpredictable. A person who intends to use one drug may receive several, and no single-substance treatment plan accounts for that reality on its own.

What is polysubstance use?

Polysubstance use means using more than one substance, whether intentionally or not. Some people combine drugs on purpose, for example using a stimulant and an opioid together. Others encounter multiple substances without meaning to, because the supply is contaminated. Both patterns fall under polysubstance use, and both change how treatment should work.

The distinction matters clinically. Intentional combinations call for a treatment plan that addresses each substance a person uses. Unintentional exposure calls for overdose education, drug-checking awareness, and a supply-aware overdose response. A mobile behavioral health satellite clinic network can hold both approaches on the same unit, screening broadly and tailoring the plan to what a person is actually using.

Why is polysubstance use so common in the current drug supply?

It is common because the illicit supply is increasingly mixed, so people are exposed to combinations they did not choose. The clearest recent example is xylazine, an animal sedative found in the drug supply. In 2022, the DEA found that about 23% of seized fentanyl powder and roughly 7% of fentanyl pills contained xylazine. A person buying what they believe is a single drug may receive two or more.

The overall overdose picture is shifting at the same time. In 2024, the US recorded an estimated 80,391 drug overdose deaths, down 26.9% from 110,037 in 2023, and fentanyl-involved deaths fell from 76,282 to 48,422. Those declines are real and encouraging, and overdose still remains a leading cause of preventable death with progress spread unevenly across groups. A mixed supply means that treatment and overdose response both have to plan for more than one substance at a time.

Why do single-substance treatment models fall short?

Single-substance models fall short because they treat one exposure and leave the others in place. A program that starts a patient on medication for opioid use disorder has done something that saves lives, yet it has not addressed the stimulant that person also uses or the xylazine wound on their leg. The patient leaves with part of their care met and part ignored.

Xylazine shows why this is dangerous. It is an alpha-2 adrenergic agonist whose peripheral vasoconstriction contributes to deep ulcerative wounds and poor healing, with severe cases causing soft-tissue necrosis that can lead to amputation. Xylazine is not an opioid, so naloxone does not reverse its sedative effects, though naloxone still reverses the fentanyl. A model that assumes one drug and one antidote misses both the wound and the limits of the overdose response.

How does integrated mobile care help?

Integrated mobile care helps by putting the pieces of treatment on one unit and treating the whole person in one visit. Instead of sending a patient to a methadone clinic, a wound clinic, a counselor, and a harm reduction site separately, a mobile team can offer medication for opioid use disorder, behavioral treatment for stimulant use, wound care, naloxone, and overdose education together.

Staffing makes this work. Hire staff dedicated to the mobile program, a team that owns the route and knows the patients, rather than rotating clinicians in from a fixed site. Rotating breaks continuity and makes the mobile unit the first service cut when the fixed site loses a provider, which is the opposite of what people who use multiple drugs need. Getting the roles and schedule right is central to mobile health operations planning. For a region, a coordinated satellite clinic network across health plans can place integrated units where the need is highest.

How does polysubstance use raise overdose risk?

Polysubstance use raises overdose risk because combining substances compounds their effects and because contamination adds an antidote gap. When fentanyl is mixed with xylazine, naloxone will reverse the opioid but not the sedation from the xylazine, so a person may remain dangerously sedated even after an appropriate naloxone response. The federal government recognized this danger when it designated fentanyl adulterated with xylazine an emerging threat in April 2023.

Medication remains the strongest protection against opioid-related death. Agonist medication such as methadone or buprenorphine is associated with roughly a 50% reduction in mortality among people with opioid use disorder. In a polysubstance context, starting and keeping people on that medication addresses the opioid risk directly, while overdose education and naloxone address the parts that medication and a single antidote cannot cover on their own.

What does treatment for polysubstance use involve?

Treatment involves a plan that matches every substance a person uses, plus care for the physical harms that come with it. For opioids, that means medication for opioid use disorder, which has strong evidence behind it. For stimulants, there are no FDA-approved medications, so treatment relies on behavioral approaches. Contingency management, which reinforces goals such as attendance or reduced use, along with counseling and structured behavioral therapy, forms the core of stimulant treatment on a mobile unit.

A practical mobile plan for polysubstance use includes:

1. Broad screening for opioids, stimulants, alcohol, and other substances at intake.
2. Medication for opioid use disorder when opioids are involved.
3. Behavioral treatment, including contingency management and counseling, for stimulant use.
4. Wound assessment and care, given the rise of xylazine-related wounds.
5. Naloxone, overdose education, and a supply-aware overdose plan.
6. Scheduled follow-up with the same dedicated team to keep people engaged.

Holding all of this on one behavioral health satellite clinic network unit is what makes integrated treatment realistic for people who use more than one drug.

Frequently asked questions

Does naloxone work if a drug contains xylazine?

Naloxone reverses the fentanyl but not the xylazine. Xylazine is not an opioid, so naloxone does not reverse its sedative effects. Responders should still give naloxone for a suspected opioid overdose, then provide rescue breathing and call for help, because the person may remain sedated from the xylazine.

Are there medications for stimulant use disorder?

No medications carry FDA approval for stimulant use disorder. Treatment relies on behavioral approaches such as contingency management, counseling, and structured behavioral therapy. A mobile program can deliver these alongside medication for opioid use disorder for people who use both types of drugs.

Did overdose deaths really go down?

Yes. In 2024 the US recorded an estimated 80,391 overdose deaths, down 26.9% from 110,037 in 2023, with fentanyl-involved deaths falling substantially. The decline is meaningful, and overdose remains a leading cause of preventable death, so treatment and overdose response are still essential.

Why treat multiple substances instead of just the opioid?

Because treating one substance leaves the others in place. A person using an opioid and a stimulant needs medication for the opioid and behavioral treatment for the stimulant, and a person exposed to xylazine may need wound care. Integrated treatment addresses the full set of risks a person carries.

If your program serves people who use more than one drug, an integrated mobile unit can treat the whole picture in one place instead of scattering care across sites. Learn how a behavioral health satellite clinic network can bring medication, behavioral treatment, wound care, and overdose response together on one route.