Health-care company Johnson & Johnson said on Friday it had received a subpoena requesting documents about the sales and marketing of Procrit, a prescription treatment for anemia.

The Brightwater, New Jersey-based company said it is cooperating in responding to the subpoena that was issued by the U.S. Inspector General of the Department of Health & Human Services.

In a regulatory filing earlier this year, Johnson & Johnson said New York state Attorney General Eliot Spitzer had asked for documents pertaining to marketing and so-called off-label sales of several drugs, including Procrit.

While doctors are free to prescribe drugs as they see fit, sales representatives for pharmaceutical companies are only allowed to promote them for uses approved by the U.S. Food and Drug Administration and stated on the drug’s label.

Other drugmakers have recently come under heightened scrutiny for off-label promotions.

In May, Pfizer Inc. agreed to pay $430 million for illegal marketing of the epilepsy drug Neurontin by Warner-Lambert before that company was acquired by Pfizer.

Warner-Lambert’s sales force had promoted Neurontin for a variety of unapproved uses, including for migraines, pain and bipolar disease.

Sales of Procrit, a bioengineered version of a human protein that stimulates production of red blood cells, totaled $2.8 billion last year. It is used chiefly to treat anemia in cancer patients.

This year, however, sales have been hurt by competition from rival products such as Amgen Inc.‘s Aranesp, a longer-lasting version of the treatment.

In the second quarter, Johnson & Johnson said sales of Procrit fell 18 percent to $582 million.