Medical centers nationwide have been resorting to alternate routes as traditional providers and quantities of medicine have dried up. During the summer, just more than half of the 549 U.S. hospitals responding to a survey by the Institute for Safe Medication Practices, a patient safety group, said they had purchased one or more prescription drugs from so-called "gray market vendors"- companies other than their normal wholesalers. The U.S. Food and Drug Administration reports it is tackling the issue. "The FDA will continue its efforts to work with manufacturers to ameliorate shortages. For example, FDA already expedites requests to qualify new manufacturing sites, new production lines or new raw material suppliers to avert drug shortages," said FDA Commissioner Margaret Hamburg and Assistant Secretary for Health Howard Koh.