Media Post -- With all kinds of marketers dabbling with the likes of Facebook, Twitter, and YouTube, one group of advertisers reluctant to join the social media fray has been big pharmaceutical companies. That’s mainly because of concerns that embracing emerging Web 2.0 tools could run afoul of Food & Drug Administration regulations governing the advertising and promotion of branded drugs. The FDA hasn’t squarely addressed the role of social media in drug advertising to date. But an agency official offered some insight on the subject in a recent interview with Mark Senak, a Fleishman Hillard executive in Washington, D.C. who separately runs the EyeonFDA blog.