As opioid-involved overdoses continue to claim lives by the thousands in the United States, the FDA is warning of a new drug that can be just as fatal as opioids but unresponsive to emergency reversal treatments.

Xylazine is a sedative and pain reliever approved for veterinary use in large animals, such as horses, but it is not safe or effective in humans. It is illegal to use on humans, even in a hospital setting. The drug has been blamed for the deaths of 39 people in Jefferson County so far this year, according to Coroner Bill Yates.

Known as "tranq" on the streets, the drug causes similar side effects as fentanyl, heroin and other illicit drugs. The drug can slow a person's heartbeat and breathing, put a person in a state of unconsciousness and cause death. Side effects can last eight hours or longer. Another side effect of using the drug is constricted blood vessels, leading to deep, necrotic wounds in the skin.

Yates said in the cases in Jefferson County, the drug has been mixed with other illegal substances, such as heroin, fentanyl, cocaine, methamphetamine and counterfeit pills, and most of the time, the user has no idea.

"They don't know the drug they are ingesting. They don't know what it is," Yates said. "That makes it dangerous."

One of the deaths in Jefferson County was investigated by the Homewood Police Department. Sgt. Eric Marquard echoed Yates' concerns. He said most people who use xylazine don't know the product they are using contains it.

"You buy drugs on the street. That's really the thing with it. You don't know what's in there," Marquard added. "Street people operate off reputation. They say, 'that dope killed somebody, so it must be good."

Other areas where the drug has claimed lives include Birmingham, where there were 24 fatal cases, Bessmer, Tarrant, Gardendale, Hoover and Vestavia Hills, along with other areas in unincorporated Jefferson County.

The FDA has warned healthcare professionals that the side effects of xylazine may not be reversed by naloxone, also known as NARCAN, which is used to treat opioid overdoses. Yates and Marquard confirmed there is no field screening for the drug, and it does not react to NARCAN.

"I know they can test it in urine or any of the other normal tests they do, like if you got blood work at your doctor's office, but I don't know of a field-type test," Marquard said. "I was also told there isn't a screening test for paramedics in the field. They know the symptoms of it, but those are common symptoms.

"Narcan doesn't work. There isn't a field antidote for it. I think everyone is still trying to feel their way around it because there just isn't a lot of research on it because it's not a human drug."

Making matters worse, xylazine is not a controlled substance on a federal level, although some states have started to look at making it illegal without a prescription. Officials hope Alabama lawmakers hear their concerns.

"Now we're at a place where we're reaching out of human drugs and using animal drugs," Marquard explained. "My concern is we are always playing catch-up to cope with the new drug somebody has found, and during that time period, we are trying to learn the effects of it and what we can do about it, and we're kind of hamstrung. I wish there was a mechanism by which we could look at all the drugs that are used for analgesia, for example, for any mammal, and say, 'can we do something about regulating the use of these things?"

Marquard said law enforcement must continually look into dangerous substances that illegal drug makers add to common drugs.

"There will be something after this one," he said. "It's just something to cope with. I mean, human beings are pretty ingenious, and they will find a way to get what they want, unfortunately."

Yates said he believes there also needs to be more mental health treatment for those struggling with drug abuse.

"Health care professionals should continue to administer naloxone for opioid overdoses and consider xylazine exposure if patients are not responding to naloxone or when there are signs or symptoms of xylazine exposure (e.g., severe, necrotic skin ulcerations)," the FDA stated in a press release. "Health care professionals should provide appropriate supportive measures to patients who do not respond to naloxone."

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