The FDA last week felt it necessary to issue a Public Health Advisory reminding physicians to pay attention to their prescribing practices in patients with influenza, as it appears that physicians may have been overly enthusiastic in their use of recently approved neuraminidase inhibitors Tamiflu oseltamivir and Relenza zanamivir. But the drugs' respective marketers, Hoffmann-La Roche Inc. and Glaxo Wellcome Inc., as well as the two biotech companies that developed the drugs, believe that the agency warning will not affect sales significantly.

"Is there inappropriate prescribing? I'm sure there probably is - you're talking about a wide range of physicians," said Roger Mills, senior director of clinical research at GILD. Tamiflu was developed by Gilead Sciences Inc. (GILD, Foster City, Calif.), while Relenza was developed by Biota Holdings Ltd. (ASX:BTA; BTAHY, Melbourne, Australia).