Fentanyl, other opioid overdose deaths in ex-prisoners reflect prevention gap

Fatal drug overdose rates among adults who were recently released from an Ontario prison are much higher than those in the general population.

'There's going to be future deaths if we don't implement effective, preventative measures’ such as naloxone

When people are released from prison, they don't receive any education or warnings about their risk of fatal drug overdoses, says Dr. Nav Persaud. (CBC)

Fatal drug overdose rates among adults who were recently released from an Ontario prison are much higher than those in the general population, which points to a glaring need for more education and treatment, the physician who led the first Canadian study of its kind says.

One in 10 fatal drug toxicities among adults in the province occurred among those within one year of their release from provincial incarceration, an average of 88 deaths per year, researchers found.

For the study published in Wednesday's issue of the journal PLOS One, the investigators analyzed coroner reports with details on circumstances of death from 2006 to 2013 and matched the names to individuals released from provincial corrections facilities.

"This is obviously a high-risk population," said study author Dr. Nav Persaud, a researcher at St. Michael's Hospital in Toronto and a family doctor.

Naloxone only works to block the effect of overdoses from opioids such as fentanyl, oxycodone and methadone. (Stefan Labbe/ CBC)

Overdose death risk was highest immediately following release. About nine per cent of the deaths occurred in the first two days and 20 per cent within the first week.

The theory that the period after release is so risky is borne out by studies that suggest people become tolerant to a certain level of drug and then when they're incarcerated, use either decreases or ends. Upon release, Persaud said, if they go back to using the same amount of a substance as before, they could die of an overdose.

Preventing tragic deaths

The team was able to determine that intervention by another person, such as administering naloxone to reverse the effects of opioid toxicity, was possible in 59 per cent of the opioid-related deaths.

It's a unique aspect to the research, Persaud said.

"If you accept that each of these deaths is tragic and that there's going to be future deaths if we don't implement effective, preventative measures then it's important to ensure the measures instituted today are helping people who are being released from institutions tomorrow."

About three-quarters of those who died of an overdose were under the age of 45. While young men accounted for the bulk of deaths, in percentages, women were more susceptible to overdose death.

Naloxone only works on opioids such as fentanyl, oxycodone, methadone or heroin and must be administered by someone who recognizes the signs of overdose and responds. (OxyContin was phased out in Canada in 2012.)

In the study, 77 per cent of the deaths were related to the use of opioids, compared with 58 per cent for drug-related deaths in Ontario overall. In other studies of individuals released from incarceration, the proportion involving opioids ranged from about 59 per cent in the state of Washington to 95 per cent in England and Wales.

"The large fraction of deaths involving opioids suggests that preventive measures directed at opioids might have the largest impact, such as safer prescribing practices, opioid substitution therapies, overdose prevention education, and opioid reversal agents such as naloxone," the researchers wrote.

Persaud applauded the news that Ontario plans to make naloxone available without a prescription, including to released inmates. But he cautioned it needs to be evaluated rigorously because research from Scotland, for example, didn't point to a decrease in drug deaths overall after the kits were introduced to those released from incarceration there.

Addressing opioid prescribing by physicians is another part of the urgently needed strategy, he said.

In the Ontario study, mixed substances including at least one opioid were found in 49 per cent or 391 deaths. Cocaine was the most common non-opioid substance present, in 10 per cent or 73 fatalities.

The researchers did not have information about prior substance use or federal incarceration data. Since toxicological tests sometimes end when a potentially fatal concentration of one substance is found, the proportion of deaths attributed to one or multiple drugs could be off.

With files from CBC's Amina Zafar