At issue is language in a drug labeling rule from 2006 that effectively limits when people can sue in state court over injury claims involving medications. The FDA contends federal regulations prevail when there is a conflict with state law. This concept is called pre-emption.

Internal agency documents showed that career officials opposed this approach, according to a report released by Rep. Henry Waxman, chairman of the House Oversight and Government Reform Committee. In the past, the agency had viewed private suits as an additional layer of protection against unsafe drugs, the report said.

"Much of the argument for why we are proposing to invoke pre-emption seems to be based on a false assumption that the FDA approved labeling is fully accurate and up-to-date in a real time basis," the report quoted Dr. John Jenkins, who oversees FDA's new drug reviews, as saying. "We know that such an assumption is false."