WASHINGTON (AP) -- The Food and Drug Administration asked Congress on Tuesday for authority to dictate label changes for drugs to end the type of haggling with pharmaceutical companies that delayed warnings to Vioxx users about potential heart problems.

Sandra L. Kweder, FDA's deputy director for new drugs, told the Senate Committee on Health, Education, Labor and Pensions that the ability to require changes in labels "would be helpful."

After the dangerous side effects of Vioxx were known, negotiations between the FDA and its manufacturer, Merck & Co., over what a warning should say, delayed getting the information out.

"The lapse from my perspective was the delay that it took to get that information into the labeling," Kweder told the panel. "We had to negotiate with the company how the specific language should be worded."

The authority to dictate the labeling language would have helped, she said, but so would the Bush administration's newly announced policy to publicize warnings before such sticking points are worked out.

Merck pulled Vioxx from the market Sept. 30 after heart problems were reported in some users. Similar questions were later raised about other so-called Cox-2 inhibitors -- Bextra and Celebrex -- prompting the FDA to have an advisory panel to look into the matter.

The advisory panel on Feb. 18 decided that the arthritis drugs' benefits outweighed its risks of heart problems and strokes but suggested the products carry strong warnings.

On Monday, Massachusetts-based Mogen Idec Inc. and Elan Corp. announced they were pulling a drug to treat multiple sclerosis after it triggered a serious disease in two patients -- killing one of them -- when taken with other drugs.

Congress is considering legislation to tighten rules on how the government keeps track of the safety of drugs after the FDA approves them.

The Bush administration announced last month it will set up an independent Drug Safety Oversight Board to monitor FDA-approved medicines once they're on the market and update physicians and patients with emerging information on risks and benefits.

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