Reps. John Dingell and Bart Stupak aren't only interested in Lipitor advertising. In the wake of the release of Enhance trial data, the duo sent letters to Merck and Schering-Plough vowing an investigation and making clear that DTC ads for the drug would be a major focus.

“Given the frequency of Vytorin advertisements, it concerns us that a study showing that Vytorin provides no increased benefit was not issued for nearly two years while (DTC ads) were carried on the airwaves,” they wrote. “This situation raises concerns that the drug companies and their advertisement agencies profited at the significant expense of patients' health.”