Nothing like being the center of attention. That’s where Merck and Schering-Plough find themselves now that the US Department of Justice and 35 state attorneys general are investigating the marketing of the controversial cholesterol pill.

The Justice Department’s civil division sent Merck a letter dated September 10 to say it is investigating whether the drugmakers improperly promoted Vytorin and, as a result, prompted false claims to be submitted to federal health care programs, according to a Merck filing with the Securities and Exchange Commission (see page 21).

At the same time, a group of 35 state attorneys general are jointly investigating whether the drugmakers violated state consumer protection laws, and they have sent five “civil investigative demands” to Merck seeking info. Merck had previously received subpoenas from the New York and New Jersey state attorneys general and a letter from the Connecticut attorney general seeking info.

The inquiries follow investigations already under way by various Congressional committees (look here and here), which are exploring the way data collected in two clinical trials - known as Enhance and Seas - were handled, as well as the aggressive promotion of Vytorin and Zetia (which, along with Zocor, comprises Vytorin). The trial results, which raised questions about Vytorin’s safety and effectiveness, and ensuing scrutiny have caused Vytorin sales to decline. The FDA, meanwhile, is looking at potential links to cancer.