Last year there were 156 heroin-involved deaths in King County, up from 99 the year before.
"It's really upsetting to see those numbers continue to go up," said lead study author Caleb Banta-Green, with University of Washington's School of Public Health.
The migration to heroin began when time-release Oxycontin was reformulated in 2010 and it and other painkillers became harder to get.
Suddenly heroin was cheap and readily available. However, treatment was not.
"Unfortunately we didn't have an ample supply of treatment for those folks, so it's not a surprise that we're seeing an increase in those deaths," he said.
Although treatment is catching up, attitudes haven't changed. Banta-Green says there's is still a stigma attached to addiction so addicts still aren't getting help they need.
Meanwhile, heroin addiction is becoming more widespread.
"We certainly have more young adults, but what's going on right now is just a greater level of deaths across the board."
Younger addicts, those under 30, prefer heroin on its own. Older addicts are mixing it with meth.
"What happens is that methamphetamine speeds you up. It's a stimulant. It makes your heart rate go up. You need more oxygen for this muscle that's working really hard. Meanwhile the opiates are slowing down your breathing. So you need more oxygen here and your body's slowing down your breathing. So that's a deadly combination," said Banta-Green.
Which is why the death rate keeps climbing.
"It might slow down some, but I do think it will go up a little bit more unless we do something pretty radical."
The drug naloxone marketed as Narcan can reverse a drug overdose.
In Washington state, opiate users and their family members can obtain a prescription to have it on hand the same way epi-pens are used to reverse allergic reactions.
For more information on Narcan, click on this this link.