Fentanyl took the lives of more than 600 people in San Francisco in 2023.
Now, experts say fentanyl is being laced with a new drug that could lead to an even greater toll.
"The city of Chicago, Philadelphia, Indianapolis, and also Toronto and Vancouver are seen Medetomidine adulterating the fentanyl drug supply. This is a very potent and dangerous animal tranquilizer," said San Francisco Supervisor Matt Dorsey.
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Dorsey sent a letter to the city's health department and the medical examiner's office asking that the potent animal tranquilizer be added to the hundreds of drugs tested every year, giving San Francisco a chance to respond.
"I want to make sure that San Francisco is ready for this. I know that in Philadelphia, just in the last month, in three to four days, there were more than 600 people hospitalized from Medetomidine because it was laced with fentanyl drug supply," said Dorsey.
UCSF's Dr. Daniel Ciccarone has been studying drugs for decades.
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"The concern is that because it's sedating, that could go in the wrong direction when you're already on sedating opioid like fentanyl, now you have two sedating drugs. A double downer and that will increase the risk for overdose," said Ciccarone.
We got a rare look inside the San Francisco Medical Examiner's toxicology lab. More than 200 substances are tested for every case.
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Dr. Luke Rodda, San Francisco's chief forensic toxicologist, said they are constantly detecting different types of drugs
"The last several years, we have noticed drugs such as Xylazine but also Bromazolam -- both designer or drugs that were previously used in other areas of our industries such as veterinary drugs -- also been found in decedents of an accidental overdose," said Dr. Rodda.
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Now they have Medetomidine to add to the list.
"We periodically update our test regime when feasible and that's certainly a substance that we would add to our list testing regime," said Dr. Rodda.
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