Vioxx case shows need for tougher drug testing

CBC News

TORONTO - Drug regulators should require prescription drugs to be tested more thoroughly, according to industry analysts. On Thursday, Merck and Co. pulled its popular arthritis medication, Vioxx, off the market everywhere after clinical tests showed patients who took the drug for more than 18 months had an increased chance of suffering a heart attack or a stroke.

The three-year study hoped to show a 25-milligram dose of Vioxx helped to prevent colon cancer. FROM SEPT. 30, 2004: Heart attack risk prompts recall of arthritis drug When Vioxx came on the market five years ago, it was hailed as a safer drug for people with severe arthritis. Such new drugs are tested in clinical trials, but most only follow patients for a few months. "This is the usual approval process for marketing in Canada," said Dr. Marie Valois of Health Canada in Ottawa. Signs of trouble began to appear once Vioxx was approved for sale.

A study published in The New England Journal of Medicine 2000 showed it caused fewer stomach ulcers than another painkiller, Naproxyn, but Vioxx seemed to increase the risk of heart disease. Merck said Vioxx wasn't the problem and Naproxyn must somehow protect people from getting heart attacks.

In August 2001, a second study in the Journal of the American Medical Association showed an association between Vioxx and heart attacks. Health Canada and the U.S. Food and Drug Administration then ordered new warning labels for Vioxx and similar drugs.

"I think the FDA should've been out there demanding more data from the company," said Jillian Clare Cohen, a drug industry analyst and a professor of pharmacy at the University of Toronto.

FROM FEB. 27, 2002: Researchers raise warning about arthritis drug Longer trials

About one year ago, a third study on Vioxx in the journal Circulation suggested a heart attack risk. By then, Merck's study testing Vioxx for the prevention of colon cancer was underway. The Vioxx case demonstrates flaws in the drug approval system in Canada and the U.S., said Dr. Jim Wright, head of the Therapeutics Initiative at the University of British Columbia. "Where they can anticipate that there will be widespread use, they should mandate a longer term trial, and make it conditional on the continued licensing of the drugs," said Wright, whose group reviews drugs for B.C.'s healthcare plan.

Health Canada isn't promising any major changes in the way it approves new drugs or monitors medications once released on the market. The department said it will take a closer look at Vioxx competitors such as Celebrex to ensure the related drugs aren't capable of causing the same problems. On Friday, a Montreal woman sought court approval to start a class action suit against Merck and Co. The woman's lawyer said it would be weeks before the court decides if the suit can go ahead.