At one point on Friday, every available Springfield Fire and Rescue Division ambulance was tied up, according to Captain Charles Alexander.

The department hasn’t gotten to the point where they weren’t able to respond to a call, he said, but if ambulances continue to be tied up with overdose calls, fire engines could begin to be dispatched for EMS runs.

“It’s very possible that people could see delayed response times,” Alexander said.

In the past couple days, the department’s emergency run volume has been about 10 to 15 percent above average.

This spike comes about a week after the county reported double the normal overdose-related ER visits in a 24-hour period from Jan. 17 to 18.

We are checking to see if there were any overdose deaths reported over the past 36 hours.

Patterson said the rash of overdoses seen in the past few weeks has been due to synthetic fentanyl. Users are taking drugs they believe to be heroin at a dosage they’ve previously taken, but are in fact taking fentanyl, a much stronger drug.

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Naloxone supplies in the county are starting to run low, and the state health department has promised to replenish the supply by Monday.

The health department’s alert said Springfield Regional Medical Center’s emergency department had run out of nasal Narcan and was using IV naloxone instead, but a spokesman for the hospital said the supply was low but not completely out.