Amgen and Johnson & Johnson strengthened the label warnings for their widely used anemia drugs yesterday, placing further emphasis on the risk that the medicines could cause heart attacks, a worsening of cancer and death.
The changes, made in consultation with the Food and Drug Administration, come after a year in which accumulating data have suggested that the drugs -- Amgen's Epogen and Aranesp, and Johnson & Johnson's Procrit -- can be dangerous if overused.
The new warnings also state for the first time that the drugs' risks for cancer patients cannot be excluded even at doses previously considered safe and routinely used.
The warnings could contribute to a decline in use of the drugs that is already well under way. But analysts said in general that the new labeling was not as restrictive as it could have been.
James F. Reddoch, an analyst at Friedman, Billings, Ramsey, called the label changes ''not bad,'' and said in a note to clients that it was now less likely that insurance companies would further restrict reimbursement for the drugs.
Amgen's shares fell 17 cents yesterday to $56.03, while Johnson & Johnson's rose 68 cents to $64.59.
The drugs are used by about one million Americans a year, mostly people with anemia caused by cancer chemotherapy or kidney failure. Combined sales worldwide were nearly $10 billion last year.
The main factor expected to depress sales of the drugs in the coming year is a new reimbursement policy by Medicare. Amgen said yesterday that it would formally ask the Centers for Medicare and Medicaid Services, or C.M.S., to overturn that policy.
Medicare's new policy applies to patients with anemia caused by chemotherapy. Medicare cuts off reimbursement for the drugs once a patient's hemoglobin -- the component of red blood cells that carries oxygen -- rises above 10 grams for each deciliter of blood.
Amgen said the new labels on the drugs support its cause. For cancer patients, the label calls for using the lowest possible dose that allows a patient to avoid blood transfusions, with hemoglobin levels not to exceed 12 grams for each deciliter.
''The label gives physicians discretion between 10 and 12,'' Kevin W. Sharer, Amgen's chief executive, told securities analysts yesterday. ''That's the main point. And the C.M.S. decision does not.''
But F.D.A. officials said that the Medicare decision was consistent with the new label.
''This is not a target,'' Dr. Richard Pazdur, the director of the agency's cancer drug office, said about the hemoglobin level of 12. ''This is an upper boundary for safety concerns.''
Medicare has said that it cannot overturn its decision without new evidence. Amgen said it would present some new evidence, including information showing that more cancer patients are now needing blood transfusions. But some analysts were skeptical that the company would succeed in overturning Medicare's decision.
The new labels came after the F.D.A. held two advisory committee meetings to consider the safety of the drugs. The agency had first slapped a so-called black box warning, the toughest kind, on the drugs in March as an interim measure.
For patients with kidney failure, the label calls for hemoglobin levels to be maintained at between 10 and 12. That is perhaps a bit less restrictive than the label in March.
But new wording in the label calls for doctors to exercise restraint or possibly discontinue use for patients who do not reach the desired hemoglobin levels after 12 weeks of treatment.
Until now, dialysis centers have tended to give such patients astronomical doses in an effort to raise their hemoglobin levels.
Joel Sendek said in a note to clients that the new label would reduce sales by ''eliminating the exorbitant doses given to those patients who have historically been a major source of revenue for Amgen'' and for dialysis centers.
