Drugmaker Wyeth is suing the Food and Drug Administration to block the sale of a generic rival to its intravenous antibiotic Zosyn, claiming the generic is not an equivalent product and could harm critically ill patients.

Wyeth this morning is filing a federal lawsuit against the FDA, seeking both a temporary restraining order and a preliminary injunction. The lawsuit seeks to prevent Orchid Pharmaceuticals from selling a generic version of Zosyn that the FDA approved last week.

Wyeth's head of global medical affairs, Joe Camardo, says patient safety is at stake and that Orchid's product could lead to preventable medical errors.

The lawsuit was filed in U.S. District Court in Washington, D.C.