WASHINGTON  Pressed by industry lobbyists, White House officials on Wednesday assured drug makers that the administration stood by a behind-the-scenes deal to block any Congressional effort to extract cost savings from them beyond an agreed-upon $80 billion.

Drug industry lobbyists reacted with alarm this week to a House health care overhaul measure that would allow the government to negotiate drug prices and demand additional rebates from drug manufacturers.

In response, the industry successfully demanded that the White House explicitly acknowledge for the first time that it had committed to protect drug makers from bearing further costs in the overhaul. The Obama administration had never spelled out the details of the agreement.

“We were assured: ‘We need somebody to come in first. If you come in first, you will have a rock-solid deal,’ ” Billy Tauzin, the former Republican House member from Louisiana who now leads the pharmaceutical trade group, said Wednesday. “Who is ever going to go into a deal with the White House again if they don’t keep their word? You are just going to duke it out instead.”