Opioid-related overdose deaths in Massachusetts declined by roughly 5 percent since the same time last year — but despite these improvements, Gov. Charlie Baker says potent synthetic drugs like fentanyl are holding the state back from tackling the problem.

“The curveball in this was the arrival of fentanyl, which wasn’t really part of the conversation a couple years ago,” Baker said in an interview with Boston Public Radio Thursday. “If you were to take fentanyl out of the mix, the progress that we’re making on heroin and opioids would look a lot more significant.”

According to the state department of health’s quarterly report on opioid statistics, the first six months of 2017 have shown an estimated 5 percent drop, from 978 deaths to 1,031 during the January-to-June period of last year.

“You hesitate to draw too many conclusions from two months … but the way I’ve been thinking about this is, for 15 years, every single quarter, year over year, the number went up, and it went up by a lot,” Baker said. “The fact that the first two quarters of [fiscal year 2017] over the first two quarters of [fiscal year 2016] it went down 5 percent, that is a change from something that has had a trajectory that’s only gone one way for a long time. We broke the trajectory, that’s a good thing.”

Baker attributed the decline to a state-wide bipartisan fight against opioid abuse, including a prescription monitoring program, public information disseminated in middle and high schools across the state, a medical program requiring opioid education tests for medical professionals and the distribution of the overdose-reversing drug Narcan.  

“We have a long way to go on this, and we’ll be talking more about some things I think we’re going to pursue in the future in the next month or so," Baker said.

To hear Gov. Charlie Baker’s full interview with “Boston Public Radio,” click on the audio player above.