Health Canada said Wednesday it is considering regulating the popular pain killer tramadol as an opioid, after seeing a spike in prescriptions over the past several years.

Tramadol has been marketed as a non-opioid in Canada for more than a decade, despite concerns raised by the government agency in 2007 that it could be abused and result in overdose and death.

A classification change would subject it to tighter controls and enhanced reporting.

Health Canada spokeswoman Anna Maddison said its original assessment "suggested that tramadol had lower potential for abuse than other prescription opiates."

But, she added, "In response to recent data regarding increasing tramadol prescriptions and quantities dispensed, Health Canada launched a review of scientific evidence and current use patterns with tramadol."

Tramadol prescriptions increased by 30 percent from 2012 to 2016, according to an analysis of opiod-prescribing trends released Wednesday by the Canadian Institute for Health Information (CIHI).

"Once this review is complete, Health Canada will consider whether scheduling tramadol under the CDSA (Controlled Drugs and Substances Act) is appropriate," said Maddison.

The World Health Organization and the United States already classify tramadol as an opioid.

The CIHI data showed all opioid prescriptions in Canada rising by seven percent from 20.2 million in 2012 to 21.5 million in 2016.

Six opioids accounted for more than 96 percent of all opioid prescriptions: hydromorphone, morphine, fentanyl, oxycodone, codeine and tramadol.

But the overall number of doses of opioids dispensed to Canadians, the report added, fell by slightly less than five percent from 238 million to 226 million during the period.

"The rate of decline has accelerated with heightened awareness of the opioid crisis," the report said.

Overprescribing has been blamed for an opioid crisis sweeping North America.

According to Canada's public health agency, more than 2,800 people died of opioid overdoses in 2016, and preliminary figures from coroners suggest that figure will be higher this year.