On Tuesday, as the actor Roseanne Barr grappled with the public outcry over an offensive tweet that drove ABC to cancel her eponymously named show, she returned to Twitter to apologize and offer excuses. It was Memorial Day, she said. It was early in the morning. “I was ambien tweeting,” Barr told her followers.

Barr’s reference to Ambien, the signature insomnia drug from the pharmaceutical company Sanofi-Aventis, set off a wave of social media commentary and news stories about the medication. And it set off a dash inside the U.S. offices of the French drug company about whether—and how—to respond.