A Canadian court recently authorized a class action suit against Merck & Co over its Vioxx painkiller without including the ``vast majority'' of users who took the medicine and didn't claim injuries, the company said.

Justice Andre Denis of the Quebec Superior Court of Justice ruled a class action may not be able to handle individual claims, Whitehouse Station, New Jersey-based Merck's Merck Frosst unit said in a statement sent by Canada Newswire today. In a separate statement, Merck's opponents described it as the first consumer class action against Vioxx in North America.

"Although we would have preferred that no class be authorized, Merck has the right to move to de-authorize the class at a later date,'' Andre J. Payeur, the company's lawyer, said in the statement.