News in brief - May 2, 2005

Flu sample mishap - FDA OKs some silicone breast implants - FDA warning on antipsychotic drugs - New EPA guidelines for assessing carcinogen exposure risks

Flu sample mishap

Laboratories in the United States and several other countries responded to appeals by public health authorities and began destroying samples of a potentially dangerous strain of H2N2 flu virus incorrectly included in a proficiency panel.

The virus, which was responsible for the Asian flu pandemic of 1957, is not believed to have escaped into the community, said Julie Gerberding, MD, director of the Centers for Disease Control and Prevention.

The virus was sent to more than 4,000 laboratories, some in physicians' offices, in panels created by Meridian Bioscience of Cincinnati as tests for certification.

All the labs that received the virus were asked to immediately destroy it and to closely monitor the health of their workers. The CDC is also working to tighten its restrictions on dangerous viruses.

Canadian health officials reported the presence of the dangerous strain of virus in March when it was identified after apparently contaminating a routine sample from a patient that was being screened at a lab that had received one of the proficiency panels.

FDA OKs some silicone breast implants

A Food and Drug Administration advisory panel that met in mid-April to provide advice to the agency on whether silicone breast implants should be sold more widely delivered a very mixed message.

The panel voted 5-4 April 12 against the approval of implants manufactured by the Inamed Corp. and reversed itself the next day in a 7-2 vote to approve sales of an implant manufactured by the Mentor Corp.

Since 1992, silicone implants have been available only to breast cancer patients participating in clinical trials because of concerns that silicone leaking from the implants could cause serious health problems.

Saline implants, judged to be the safer of the two, are the only implants available widely, and they have been criticized for looking less natural than the silicone implants.

The FDA advisory panel met in 2003 and voted to recommend that the silicone implants be approved, although only when a list of conditions was met. In January 2004, however, the FDA rejected that advice and denied approval of the implants, citing the need for additional data.

FDA warning on antipsychotic drugs

The Food and Drug Administration is asking that a black-box warning be placed on several drugs that are frequently used "off label" to treat behavioral disorders in elderly patients with dementia. The agency issued a public health advisory April 11.

The drugs, which include Zyprexa and Risperdal, were shown to increase the risk of death among elderly patients, primarily due to heart failure or infections, such as pneumonia. These second-generation antipsychotics are approved for treating schizophrenia and were thought to be safer than drugs, such as Haldol, that they replaced.

The FDA said it also is considering adding a similar warning to the label of older antipsychotic medications because the limited data available suggest that they cause a similar increase in mortality.

The agency said it had analyzed 17 placebo-controlled trials performed with olanzapine (Zyprexa), aripiprazole (Abilify), risperidone (Risperdal) or quetiapine (Seroquel), and 15 of the trials had shown increases in mortality in the drug-treated group compared with the placebo-treated group. The studies had enrolled a total of 5,106 patients.

New EPA guidelines for assessing carcinogen exposure risks

The Environmental Protection Agency released March 29 updated principles and procedures to guide EPA scientists in assessing cancer risk from exposures to environmental pollutants.

The two documents, a cancer guideline as well as a supplemental guidance focusing on assessing susceptibility from early-life exposure to carcinogens, reflect what the agency termed was its "evolving approach to cancer risk assessment."

Both were generally complimented by environmental groups.

The cancer guideline, last revised in 1986, reflects changes in scientific knowledge, setting forth updated recommendations to guide assessment of cancer risk resulting from exposure to chemicals or other agents in the environment. The document is also used to inform decisions about risk assessment procedures.

The additional supplemental guidance, which describes possible approaches to assess cancer risk exposures in children from birth to 16 years, is the first such agency document specifically related to children and is consistent with a 1994 recommendation by the National Research Council.

"These guidelines will help us apply the most up-to-date science and to incorporate new science as it becomes available," said Tim Oppelt, acting assistant administrator for the Office of Research and Development. "EPA's guiding principle is that our cancer risk assessments be public health protective."