Published
Medically reviewed by Danesh Alam MD, DFAPA, DFASAM
Xylazine and nitazenes are two dangerous substances now found in the illegal drug supply, often mixed with fentanyl. Xylazine, called "tranq," is an animal sedative that naloxone does not reverse and that can cause serious wounds. Nitazenes are synthetic opioids, some stronger than fentanyl, and an overdose may need more than one dose of naloxone.
If someone cannot be woken or is not breathing normally, call 911 now and give naloxone if you have it.
What is xylazine?
Xylazine is a sedative approved only for animals. It is not an opioid. The CDC says it is "also called 'tranq' or 'tranq dope'" and that it "can slow down the brain and breathing, make the heart beat slower, and lower blood pressure." CDC: What you should know about xylazine. The FDA says plainly that "xylazine is not safe for use in humans." FDA: Xylazine alert.
Xylazine is usually mixed into other drugs, most often fentanyl, and it can also be mixed into heroin and cocaine. People may not know it is there. According to the CDC, the DEA has seized mixtures of fentanyl and xylazine in 48 of 50 states. The CDC calls xylazine especially dangerous when combined with opioids like fentanyl, since both can slow breathing.
A newer veterinary sedative, medetomidine, has also turned up mixed with opioids in some U.S. cities. Like xylazine, it cannot be reversed with naloxone. During a 2024 cluster of overdoses in Chicago, most patients had an unusually slow heart rate. CDC MMWR: Medetomidine overdoses in Chicago
What are nitazenes?
Nitazenes are a group of synthetic opioids first developed as possible pain medicines about 60 years ago. None was ever approved for medical use in the United States. Potency varies by type: the CDC reports that some, such as isotonitazene and protonitazene, are far stronger than fentanyl, while metonitazene is roughly as strong as fentanyl. CDC MMWR: Nitazene-related deaths
Researchers report that nitazenes are "increasingly found mixed with or (mis)sold as heroin and in falsified" medications, so people can take them without knowing. Harm Reduction Journal: Nitazene test strips That includes fake pills made to look like real medications. Nitazenes are also often left off standard toxicology tests, so they can be missed even after an overdose. CDC MMWR: Nitazene-related deaths
Are xylazine and nitazenes in Florida?
Xylazine is, according to state death data. In 2023, Florida medical examiners found xylazine in 550 people who died and listed it as a cause of death in 340 of them. Every one of those deaths also involved other drugs. In the medical examiner district covering Palm Beach County, xylazine was found in 36 deaths. Florida Medical Examiners Commission: 2023 drug report
Florida lists both xylazine and nitazene derivatives as Schedule I controlled substances, its strictest category. FDA-approved veterinary xylazine is exempt. Florida Statutes 893.03 Nitazenes are harder to track: the state's medical examiner report does not count them separately, and routine tests can miss them, so there is no statewide figure.
Does naloxone work on xylazine and nitazenes?
Always give naloxone for a suspected overdose, even if you think xylazine or nitazenes are involved.
- Xylazine: "Naloxone will not reverse the effects of xylazine," the CDC says. But xylazine is usually mixed with opioids, and naloxone reverses the opioids. In Florida's 2023 data, no death involved xylazine alone. Because xylazine slows breathing, the CDC says rescue breaths are "especially helpful."
- Nitazenes: naloxone has reversed nitazene overdoses, "but multiple doses might be needed," according to the CDC. In a small study of emergency department patients, people with nitazene overdoses received more naloxone doses in the hospital than people with fentanyl-only overdoses. JAMA Network Open: Naloxone in novel potent opioid overdoses
The CDC also notes that "more than one dose of naloxone may be required when stronger opioids like fentanyl are involved," and that naloxone will not harm someone overdosing on something other than opioids. CDC: Lifesaving naloxone
What to do if you think someone is overdosing
Signs of an opioid overdose include being unable to wake up; slow, shallow, or gurgling breathing; blue or gray lips or nails; and pinpoint pupils. CDC: Responding to an overdose If you are not sure, treat it as an overdose.
- Call 911.
- Give naloxone if you have it, following the package directions. If there is no response, a second dose may be needed.
- Support breathing. If the person stops breathing, give rescue breaths if you can. NIDA: Xylazine
- Lay them on their side to prevent choking.
- Stay with them. The CDC advises staying until help arrives or for at least four hours, to make sure their breathing stays normal.
Florida's Good Samaritan law protects a person who seeks help in good faith during an overdose, and the person overdosing, from arrest and prosecution for certain drug possession and paraphernalia offenses when the evidence was found because they sought help. Florida Statutes 893.21 It does not cover every offense. If you see an overdose, call 911.
Why does xylazine cause wounds?
Repeated xylazine use can cause painful skin and soft-tissue sores that are hard to treat. Left untreated, they can become infected and, in rare severe cases, lead to amputation. NIDA notes that some clinicians see these wounds even in people who smoke or snort xylazine rather than inject it. NIDA: Xylazine The CDC warns that the wounds "may become infected and worsen quickly." CDC: What you should know about xylazine
If you notice a sore that is not healing, or one that is spreading, red, or painful, get it checked by a medical provider early, and mention possible xylazine exposure. Routine toxicology screens do not detect xylazine, so the clinician may not know otherwise. FDA: Xylazine alert
Can test strips detect xylazine and nitazenes?
Test strips can show whether some of these substances are present, but no strip can show that a drug is safe.
- Fentanyl test strips are made to check opioids, stimulants, and pills for fentanyl. Separate xylazine test strips are sold commercially. CDC: What you should know about xylazine
- Xylazine strips can miss it. In a Rhode Island study of drug residue samples, the strips missed most of the samples in which a lab found xylazine. Drug and Alcohol Dependence Reports: Xylazine test strips
- Nitazene strips went on sale in 2024. Lab studies found they detect most nitazene types but miss some, and that high levels of caffeine, a common cutting agent, can cause false positives. Harm Reduction Journal: Nitazene test strips; Harm Reduction Journal: Nitazene test strip evaluation
A negative result does not mean a drug is free of these substances. In Florida, testing products used only to check whether a drug contains fentanyl or xylazine are not considered drug paraphernalia. Products that can measure the amount or strength of a drug are not covered by that exception. Florida Statutes 893.145
Where can I get naloxone in Florida?
Naloxone nasal spray is sold over the counter in all 50 states, with no prescription needed. CDC: Lifesaving naloxone In Florida, iSaveFL, supported by the Department of Children and Families, offers free naloxone and a locator to find it near you. Our guide to Narcan and naloxone explains how it works.
If someone in your home uses opioids or other street drugs, keep naloxone where everyone can find it.
How are xylazine and nitazenes treated?
Treatment starts with an assessment. For many people that means medically supervised withdrawal, followed by ongoing care for the substance use disorder. NIDA notes there is no xylazine-specific diagnosis yet. Early research suggests withdrawal may be more intense when xylazine and fentanyl are used together, but more study is needed. NIDA: Xylazine
The period right after detox carries real risk. Tolerance drops quickly, and MedlinePlus notes that "most opioid overdose deaths occur in people who have just detoxed." MedlinePlus: Opioid withdrawal That is one reason medications for opioid use disorder matter. NIDA describes methadone, buprenorphine, and naltrexone as effective, FDA-approved treatments, and says people treated with methadone or buprenorphine are less likely to die or have an overdose than people who receive no treatment. NIDA: Medications for opioid use disorder
For confidential treatment referrals at any hour, call SAMHSA's National Helpline at 1-800-662-4357. It is free and available in English and Spanish. SAMHSA: National Helpline If you or someone you love is in emotional crisis, call or text 988. 988 Suicide & Crisis Lifeline
Frequently asked questions
Is xylazine an opioid?
No. Xylazine is a non-opioid sedative approved only for animals. It is dangerous because it is usually mixed with opioids like fentanyl, and naloxone does not reverse its sedating effects.
What is "tranq dope"?
"Tranq" is a street name for xylazine. "Tranq dope" usually means xylazine mixed with fentanyl or another opioid.
Are nitazenes stronger than fentanyl?
Some are. Potency varies widely across the nitazene family: some types are far stronger than fentanyl, and others are about as strong.
Should I still give naloxone if I think xylazine is involved?
Yes. Naloxone reverses the opioids that are usually mixed with xylazine. Call 911, give naloxone, support breathing, and stay with the person.
Will a fentanyl test strip detect nitazenes?
Fentanyl test strips are made to detect fentanyl. Separate nitazene strips exist, but lab studies found they miss some nitazene types. A negative result on any strip does not mean a drug is safe.
Getting help at Ambrosia
Midwest Detox at Ambrosia in West Palm Beach provides detoxification with 24/7 medical supervision by physicians and nurses, for adults and adolescents. Admission and the plan of care are based on an individual clinical assessment. Medication-assisted treatment is provided through our detox center, so ask about medication for opioid use disorder when you call. The medical detox program page explains the first days.
Wondering how quickly care can start? Read how fast you can get into detox. To plan the next step, read what happens after detox.
To talk with admissions or ask about current availability, call (888) 492-1633 or request a callback.