Plavix, a popular blood-thinning drug, is the target of multiple lawsuits by users and third-party payers, who charge that manufacturers Bristol-Myers Squibb and Sanofi-Aventis US marketed the drug in disregard of its potential health risks.

In five suits filed Monday in federal court in Trenton, N.J., and two filed in October, the plaintiffs claim that the manufacturers promoted Plavix and aspirin together as a regimen for the prevention of blood clots, when safety of that therapy was unknown.