A New Jersey appellate court upheld the national class action status of the Vioxx lawsuits. This is significant for plaintiffs who’ve brought suit against Merck, the manufacturer of the once popular arthritis drug. The lawsuit, which seeks reimbursement for as much as $9.6 billion of Vioxx purchases, could significantly complicate Merck’s defense efforts as it battles thousands of cases brought by individuals. If it goes to trial, the stakes will be large and the plaintiffs will face a lower bar to prove their case than in the personal-injury cases that have been seen so far. A loss in the case would trigger triple damages under state law. That could increase pressure on Merck to consider a settlement, at least for some cases, which it so far has resisted, experts said.