NEWARK, N.J. — Drugmaker Merck & Co. is not liable for the medical monitoring of Vioxx users not claiming injury, the New Jersey Supreme Court ruled Wednesday.

The 5-1 ruling by the state's highest court means a class-action lawsuit by people who used the once-popular painkiller will be dismissed. One justice did not participate.

The lawsuit was filed by Vioxx users who claim they have no immediate symptoms but that use of the drug gives them a greater risk of developing illness. So they want diagnostic testing to uncover any hidden or developing problems.

Because they aren't claiming they have an injury, they aren't eligible for the settlement Merck announced in November. Merck agreed to pay $4.85 billion to settle thousands of U.S. personal injury lawsuits involving a heart attack, stroke or death. Some 45,000 eligible claimants had initiated enrollment as of March 31.

The high court said that since the Vioxx users in the case don't claim injury, they "cannot satisfy the definition of harm" in seeking medical monitoring under the state's Product Liability Act.

In dissent, Justice Virginia A. Long argued that the law encompassed a broad definition of harm, and includes the concept that an "increased risk of injury that creates a need for medical surveillance" is a recognizable harm.

Whitehouse Station-based Merck applauded the majority's decision, which reinstates a trial court ruling.

"The N.J. Supreme Court has made it clear that you cannot bring a medical monitoring claim unless you allege you were injured by a product. The plaintiffs in this suit sought to recover from Merck even though Vioxx has been off the market for almost four years and they do not claim that it ever injured them," Merck lawyer Ted Mayer said in a statement.

The company also maintained there is no medical science supporting the plaintiffs' position that they need to be monitored for cardiovascular conditions nearly four years later.

A message seeking comment from a lawyer for the plaintiffs was not immediately returned.

Merck pulled Vioxx from the market in September 2004 after its own study showed Vioxx doubles risk of heart attack or stroke.

Merck shares rose 23 cents to $38.20 in midday trading.