Forty milligram OxyContin pills at Turner Drugs in London, Ontario on Friday, February 24, 2012.D
Credits: DEREK RUTTAN/ The London Free Press /QMI AGENCY
The study comes as Health Canada is poised to decide later this month whether to allow generic versions of OxyContin after Purdue Pharma's patent expires.
Almost 250,000 extra OxyContin tablets were dispensed in Canada near the Windsor-Detroit tunnel between August 2010, and February 2012 - the gap when OxyContin was still available in Canada but not in the U.S. - the Institute for Clinical and Evaluative Sciences (ICES) study says.
"These are drugs that can be highly addictive and dangerous," said co-author Tara Gomes. "From our study, it shows that they are so highly sought after that people are willing to cross international borders to get a supply of these tablets."
OxyContin was de-listed in Ontario earlier this year and a new, more resistant-to-tampering drug, OxyNEO, was introduced by manufacturer Purdue Pharma.
The same crush-resistant drug was introduced in the US in 2010 under the name OxyContin-OP.
Ontario Health Minister Deb Matthews has asked for a ban on any potential generic version.
If generic versions are allowed, it could lead to more cross-border trafficking, Gomes said.
A 390% increase in OxyContin dispensed from Canadian pharmacies near the Windsor-Detroit tunnel was limited to the roughly 18-month gap between 2010 and 2012.
"I think that we need to take that into consideration as decisions are being made about these tablets that could be more easily abused," Gomes said.
Delisting OxyContin has made a significant impact in Sarnia-Lambton, said Dr. Del Donald with the Bluewater Methadone Clinic.
Less people using the clinic are testing positive for oxycodone, he said, because OxyNEO is harder to abuse - its powder also becomes a thick gel if mixed with water or alcohol.
The OxyContin problem grew out of poor prescription regulation and a lack of understanding about appropriate opiate doses and chronic pain, he said.
"If that was known the whole time, then not near as much OxyContin would have been prescribed," he said.
A registry and photo identification program formed in 2010 to help doctors determine where patients get opiates was a big step in the right direction, Donald said.