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CDC HIV/AIDS/Viral Hepatitis/STD/TB Prevention News Update

UNITED STATES: Pfizer Warns Health Care Professionals of


Associated Press (09.10.07) - Tuesday, September 11, 2007

On Monday, the Food and Drug Administration (FDA) announced that Pfizer Inc. has notified health care professionals that its HIV drug Viracept contains traces of ethyl methanesulfonate (EMS), a potential human carcinogen.

FDA has asked Pfizer to limit the presence of EMS, a process- related impurity, in Viracept. Animal studies have indicated EMS is carcinogenic; however, no human-based data are available.

Drug maker Roche in June recalled all packs of Viracept in Europe. Pfizer, which sells the drug in the United States, has not issued a recall here. Pfizer said testing has found EMS levels in its Viracept substantially lower than the levels that prompted the European recall by Roche.

Pediatric patients on stable HIV treatment plans may continue taking Viracept, but treatment-na�ve patients should not begin regimens including Viracept until further notice. Pregnant women are advised not to start taking Viracept; those currently taking it should be switched to an alternative.

Pfizer is working with FDA on measures to keep EMS at substantially lower levels. For more information, visit


Copyright © 2007 -CDC Prevention News Update, Publisher. All rights reserved to Information, Inc., Bethesda, MD. The CDC National Center for HIV, STD and TB Prevention provides the following information as a public service only. Providing synopses of key scientific articles and lay media reports on HIV/AIDS, other sexually transmitted diseases and tuberculosis does not constitute CDC endorsement. This daily update also includes information from CDC and other government agencies, such as background on Morbidity and Mortality Weekly Report (MMWR) articles, fact sheets, press releases and announcements. Reproduction of this text is encouraged; however, copies may not be sold, and the CDC HIV/STD/TB Prevention News Update should be cited as the source of the information. Contact the sources of the articles abstracted below for full texts of the articles.

Information in this article was accurate in September 11, 2007. The state of the art may have changed since the publication date. This material is designed to support, not replace, the relationship that exists between you and your doctor. Always discuss treatment options with a doctor who specializes in treating HIV.