08/29/2013 12:59 EDT | Updated 10/29/2013 05:12 EDT

Old pain drug pulled from Canadian market; overdose, misuse potential cited

TORONTO - The maker of a prescription pain drug that has been on the market for decades has decided to discontinue making the medication.

Health Canada approved the decision, saying in a release that the risk-benefit ratio of the drug no longer supports its use.

The drug is called 282 MEP; it is made by Pendopharm, which stopped sales of the drug on July 30.

Drug safety researcher Dr. David Juurlink says the drug is a combination of Aspirin, codeine, caffeine and meprobamate and was often used for muscle pain.

It was similar to 222s, commonly used over-the-counter pain pills that combine Aspirin, codeine and caffeine, but with 282 MEP the dosages were stronger.

The addition of meprobamate was what tipped the balance on the drug, with Health Canada saying it can cause severe adverse reactions.

Juurlink, who works at Toronto's Sunnybrook Health Sciences Centre, says he's surprised it's taken so long to withdraw 282 MEP from the market.

"This is a drug that no one ever truly needed and I think caused an awful lot of toxicity," he says.

"Someone taking this drug could easily come to hospital confused, delirious, very sick, even during therapeutic dosing" — in other words, using correct dosages — "of the drugs. So I'm glad to see it go."

Juurlink says that people who are using the drugs probably have been taking them for a long time. In recent years, people needing pain relief would have likely been given a different prescription, he says.

"Its use in patients with pain over the last 15 years has been supplanted by newer drugs," he says. "In people who 20 or 30 years ago would have been prescribed 282 MEPs, nowadays they're typically prescribed another pain killer and-or a muscle relaxant or anxiety medication separately."

Juurlink says the meprobamate component of the drug made it tough to treat people who had overdosed on the drug because it triggered cardiac instability, coma and respiratory failure. "It's not uncommon to see somebody die after a large meprobamate overdose. It makes the treatment of patients very, very difficult."

The Health Canada release announcing the withdrawal of 282 MEP says distribution of the product will be phased out over the next few weeks and its DIN — drug identification number — will be cancelled on Oct. 28.

Health Canada says once 282 MEP is gone from the Canadian market, there will be no drugs containing meprobamate available for sale in Canada.