The Franklin County Coroner's Office has recorded a "dramatic increase" in overdose deaths, a total of 18 in one week.

That's about 2.5 deaths per day - and much higher than the overdose death rate in 2018 thus far, according to Franklin County Coroner Anahi Ortiz.

Ortiz says preliminary screenings show majority of the overdoses are fentanyl-related.

“Maybe there's a particular batch of fentanyl that's out that's more potent. I don't know,” Ortiz says. “Perhaps law enforcement may have a better answer to that. But in terms of what we've seen here, I can't give you the exact type of fentanyl for a few more weeks.”

A lot of the overdose deaths in the past week were concentrated in the West Side of Columbus.

“A lot more of them are on the west side in terms of this grouping of overdose deaths," Ortiz says. "So, 43223, 43222, 43204, so there's a particular batch there."

Last week saw one overdose death in Gahanna and another in Reynoldsburg.