In the old days (by which I mean five years ago), plaintiffs rarely sued medical device sales representatives and distributors in products liability lawsuits. When they were sued, it was almost always to destroy diversity jurisdiction, thereby preventing removal of the case to federal court. The question on remand—whether the plaintiff could make a colorable claim against the representative—was often decided on whether the representative could be deemed a "seller" in the chain of distribution under applicable state tort law. In some states, the answer was clearly yes. In others, no. There was nothing provocative about these fairly benign legal questions.
The golden age has ended. Nowadays, sales representatives are being sued in products cases not just because they may be part of the chain of distribution, but also because they promoted a product for an off-label use (or prevented the doctor from using the product for an off-label use) or because, under common-law negligence theories, they are alleged to have breached some newly concocted duty of care to the patient during the course of a surgical procedure: a duty to instruct the surgeon on how to use a prescription medical device, a duty to prevent the surgeon from using the device improperly, a duty to train the surgeon, and so on. The latter scenario has become an area of increasing interest within the legal community, and courts are just beginning to dissect the novel issues presented by these alleged duties, including how they jibe with black letter law on longstanding tenets like the learned intermediary doctrine.