TORONTO - Canadians are taking more prescription drugs than ever before, and increasingly those medicines are generic versions rather than brand-names, says a company that tracks worldwide pharmaceutical sales.

In a report released Thursday, IMS Health said the number of prescriptions filled by Canadians rose by more than seven per cent in 2008 over the previous year.

Prescription spending last year hit an estimated $21.4 billion, up from $20.2 billion in 2007, said IMS. In all, pharmacists countrywide dispensed 453 million prescriptions, for an average of roughly 14 per Canadian.

Brian Carter, director of external affairs for IMS Health Canada, said the 2008 rise in total prescriptions reflects a trend that's been going on for several years.

"Basically it's an increased utilization, but that's driven by things like the aging population, an increasing number of products in the marketplace and increasing awareness of consumers of the diseases they have and the drugs that are there to treat them," Carter said from Edmonton.

"That's sort of what's driving the growth in the number of prescriptions."

Steve Morgan, a health economist and researcher at the University of British Columbia, said prescription drug utilization has been steadily inching up year over year since the mid-1990s, both in Canada and elsewhere in the world.

"Many people would point to the aging of the population as a potential explanation of this," Morgan said from Vancouver. "Certainly the baby boomer generation is finding itself getting older and they're entering the years in which it can be expected that they will be filling more prescriptions over time."

"But ... we don't see that aging of the population is a big cause of drug spending or drug utilization increases."

Morgan said the greying of Canada's population accounts for an increase in pharmaceutical use of only about one per cent a year, "not by this seven or eight per cent you see in the (IMS) data."

He pointed to a proliferation of medicines developed in the last two decades and increased marketing of those products to both doctors and patients.

Consumers see commercials for specific drugs on U.S. TV channels and a variety of "reminder ads" that promote medicines using loopholes in Canada's stricter prescription drug advertising regulations, he said.

"But what's also happening is we're changing the standard of defining risk for future conditions. We've entered into a chronic disease management era."

"The focus is on trying to manage risk factors," said Morgan, so doctors are increasingly prescribing drugs to lower cholesterol levels or blood pressure, for instance, to diminish the chance of a future heart attack or stroke.

The IMS report also showed a sea-change in pharmaceutical market share, with less-expensive generic drugs overtaking brand-name medicines.

Last year, generics accounted for 51.6 per cent of all prescriptions dispensed in Canada, up from 48 per cent in 2007. Meanwhile, brand-name products claimed 48.4 per cent of the market, down from 52 per cent a year earlier.

Overall, dispensed volume of prescriptions for generic medication grew by 15 per cent in 2008, while brand-name volume dropped by 0.3 per cent, IMS said.

"The increasing use of generics is due to primarily the increasing number of brand-name drugs that are coming off patent," explained Carter. "So there are just more generic drugs that are available."

"And then there's a real focus on spending on prescription drugs by both the public and the private sectors and the desire to keep their costs under control."

Morgan said many of the blockbuster drugs developed in the 1970s and '80s, such as the class of antidepressants that includes Prozac and Paxil, are off patent and now sold in generic forms.

In fact, he said, brand-name drugs that currently command about US$74 billion of global market share will lose their patent protection in 2010-2012, including the world's Number 1 drug for sales -- Lipitor. The cholesterol-lowering medication by Pfizer currently brings in annual sales of about US$12 billion.

"And patients who used to be on the brand will be switched to generic, quite appropriately, because they're saving (money) and usually they're interchangeable," Morgan said.

The IMS report also showed that cardiovascular medications continued to lead as Canada's most prescribed drug class in 2008, followed by psychotherapeutics and gastrointestinal drugs.

Sales of prescription drugs to Canadian hospitals and pharmacies in 2008 grew 6.6 per cent in 2008, compared with a growth of 6.2 per cent a year earlier.