Health Canada is considering changing its system of licensing prescription drugs, moving to one in which the safety and effectiveness of medicines would be more closely monitored after products are approved for sale.

A discussion paper proposes progressive licensing for drugs to allow follow-up once they are being taken by large numbers of people. 

'Drug companies do have to report to Health Canada around spontaneously reported events, but those are under-reported.'— Dr. Andreas Laupacis comments on current system

Clinical trials done before drugs are brought to market are typically small; rare side-effects generally only come to light when medications are taken by many thousands of people.

The aim is to improve the ability of the regulatory system to monitor the safety of medication during the entire life cycle of a drug.

The importance of this has been underscored in recent years by the revelation that popular painkillers from the COX-2 inhibitor family raised risks of heart attack and stroke.

Ongoing surveillance

"A progressive, life-cycle approach to the regulation of drugs is meant to recognize that valuable information continues to grow over time, and that this information should be captured and incorporated into decision-making in a well-planned and transparent manner," said the discussion paper, dated Feb. 21 and posted on the department's website.

"For example, a new use may be discovered for a drug, and this is a potential benefit. Conversely, an interaction with another drug may be uncovered that could be a potential risk in some situations."

The former head of the Canadian Expert Drug Advisory Committee said he believes the proposal is probably "a step in the right direction.

"What I think they are proposing … is a more systematic approach to pharmaco-surveillance or post-marketing studies," said Dr. Andreas Laupacis of St. Michael's Hospital in Toronto.

"Drug companies do have to report to Health Canada around spontaneously reported events, but those are under-reported. It's not the drug companies' fault, but they just are, and there's no systematic look at this."

Success depends on regulatory powers

The discussion document said that a modern regulatory regime should "allow for the initial and ongoing collection, evaluation, and communication about drug information throughout the product life cycle," based on the latest knowledge on the risks and benefits of a drug.

While Laupacis thinks there is a need to follow drug safety in a more organized way, how effective the proposal will be depends on the powers given the regulatory agency, he said.

"What if, when you do one of these post-marketing surveillance, you find that a drug does has unexpected side-effects … Is Health Canada going to respond to that?"