A federal advisory panel, in response to mounting safety concerns, called on Thursday for additional restrictions on the use of anemia drugs by cancer patients.

The recommendation by a committee that advises the Food and Drug Administration could lead to an additional decline in sales for the drugs: Aranesp, made by Amgen, and Procrit by Johnson & Johnson.

But the two companies avoided the outcome they most feared: a recommendation that the drugs not be used by any cancer patients. That probably would have meant the loss of at least $1 billion in sales for each company.

“They dodged the really big bullet, but they still took some damage,” said Geoffrey C. Porges, a biotechnology analyst at Sanford C. Bernstein & Company.

Yaron Werber, an analyst with Citigroup, estimated that Amgen would lose about $125 million in Aranesp sales if the recommendations were enacted. That would be about 25 percent of Mr. Werber’s already reduced projections for 2008 sales to cancer patients in the United States. The meeting was held because eight clinical trials suggested that the drugs might make cancer worse for some patients or even shorten their lives. Cancer patients take Aranesp or Procrit to counter the anemia caused by chemotherapy.

The difficulty for the committee was that those eight studies involved high doses of the drugs. There was very little solid information on whether the drugs were dangerous at doses typically used by cancer doctors.

Faced with that information, the panel voted 13 to 1 in favor of recommending that the drugs remain available for use by many cancer patients.

But the committee then voted 9 to 5 in favor of recommending that the drugs not be used by patients with either breast cancer or head and neck cancer because the evidence of a risk was strongest for those types of tumors.

The committee also voted 11 to 2, with 1 abstention, to recommend that the drug not be used by patients being treated with the intent of curing their cancers. The definition of that category is vague, but it generally refers to patients with early-stage cancer who are undergoing chemotherapy after surgical removal of a tumor, in which the doctors hope the cancer has been eliminated. F.D.A. officials said after the meeting that most use of the anemia drugs was for patients with more advanced cancers.

The panel members also recommended that patients be made to sign consents in order to obtain the drugs. But the panel voted against carefully controlling distribution of the drugs.