麻豆传媒

SAN FRANCISCO -- Last September, opioids adulterated with a mystery ingredient sparked an outbreak of drug overdoses that flooded a southern Pennsylvania hospital with 94 patients, a toxicologist reported here.

Blood pressure readings approached 200/100 mm Hg in some patients, while others had extremely low heart rates, both unusual symptoms in overdoses, said Sarah Weiss, MD, of Reading Hospital in West Reading, Pennsylvania, during the American College of Emergency Physicians (ACEP) annual meeting.

"For the most part, they reported some version of the same thing -- they used their typical drug and it didn't feel right," she explained. Patients were often "somnolent, weak, falling down, or feeling generally unwell."

The average length of hospital stay was 3.2 days. Three patients experienced cardiac arrest in the emergency department, where one patient died. Two others died as inpatients.

It's not clear why the tainted opioids spawned overdoses that produced unexpected symptoms and often didn't respond to naloxone (Narcan) or had a limited response to it. An analysis of 49 samples turned up several common heroin adulterants such as fentanyl, xylazine (an animal tranquilizer known as "tranq"), and clonidine (a sedative/anti-hypertensive).

Out of the 49 samples, xylazine was found in 96%. According to news reports, it's been linked to overdoses and horrific skin wounds. "At higher doses, it knocks people fully unconscious. Instead of the semi-awake euphoria of opioids, those taking fentanyl cut with xylazine may black out and awaken hours later," according to .

Ninety percent of the samples included clonidine, which is . Heroin (and its metabolites) and fentanyl (and its metabolites) were each found in 86% of samples, while 43% included cocaine and its metabolites. Fourteen samples included no heroin at all.

Also present in every single sample was a chemical that's still unknown, despite months of analysis. "I don't know the influence of this chemical," Weiss said. "We've had three PhD chemists trying to make [identify] this thing."

In an interview with 麻豆传媒, Anthony Spadaro, MD, MPH, an emergency department resident physician at the Hospital of the University of Pennsylvania in Philadelphia, said that the typical signs of heroin overdose are pinpoint pupils and slow breathing, neither of which was common in the Reading outbreak. Low blood pressure is more common in overdoses than high blood pressure, he noted, and slow heart rate is not often observed.

Spadaro, who attended Weiss's ACEP presentation, said the Reading outbreak is also unusual because of the number of cases and the length of recovery time. "Most people don't need to be in the hospital for 2 days after they use heroin," he said.

"This highlights the need for policy-level changes, easier access to clean syringes, overdose prevention sites/safe consumption sites, fentanyl test strips, expanded access to methadone and buprenorphine, and more focus on helping and treatment than criminalization," he added.

During the outbreak, Weiss said that 60 patients came in with overdoses over 3 days, and another 34 came in later. A smaller nearby hospital saw 30 patients experiencing overdoses.

Average age of patients was 45.4, 84% were men, and most were Hispanic. Nearly 60% were admitted, and four were sent to the ICU and intubated. Generally, these patients had a history of opioid use.

The average duration of both bradycardia and hypertension was 43 hours. About 8% had heart rates under 40 beats/minute and 62% had rates under 60 beats/minute. Bradypnea was not noted, and there were no abnormal pupils in conscious patients.

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