Pharmaceutical giant Merck says it has reached an agreement to settle Canadian lawsuits related to its controversial pain medication Vioxx.

The New Jersey-based company says it will pay between $21.8 million and $36.9 million to settle claims with Canadians who suffered heart attacks while taking the drug.

The total payment amount will depend on the number of eligible claims and includes about $10 million in fixed fees and legal costs.

It's the latest chapter in an ongoing controversy surrounding Vioxx, which Merck once marketed as a treatment for rheumatoid arthritis.

The company stopped selling Vioxx in September 2004 after evidence showed the drug doubled the risk of heart attack and stroke. Three years later, Merck paid $4.85 billion to settle around 50,000 lawsuits.

In November, the U.S. justice department ordered Merck to pay an additional US$950 million and plead guilty to a misdemeanour charge of marketing Vioxx as an arthritis medication before receiving government approval.

Merck has maintained it did no wrongdoing and said the settlements were not an admission of liability, adding the government acknowledged that there was no basis to conclude that upper-level management was involved in the violations.

The company reiterated that position as it announced a resolution to the Canadian lawsuits.

"Merck continues to believe that the evidence shows the company acted responsibly with Vioxx, from the careful study in clinical trials involving about 10,000 patients before its approval by regulatory authorities around the world, through the careful safety monitoring while Vioxx was on the market, right up through the decision to voluntarily withdraw the medicine in September 2004," the company said in a statement.