Tamiflu to Be Used With Caution

Injudicious use of the flu drug oseltamivir (Tamiflu) may make the drug resistant to avian strains.

Three articles published in the December 2005 issue of the New England Journal of Medicine address questions related to avian flu treatment with Tamiflu. Tamiflu is an antiviral drug, a neuroaminidase inhibitor used in the treatment of influenza. It is marketed by Hoffman La Roche (Basel, Switzerland).

Dr. Menno T. de Jong of the Hospital for Tropical Diseases (Ho Chi Minh City, Vietnam) and colleagues describe the isolation of oseltamivir-resistant strains of the avian flu strain H5N1in two patients who died of infection. One, a 13-year-old girl, had started taking the drug within 48 hours of the onset of her symptoms. In her case, the development of drug resistance appeared to be associated with a worsening clinical course.

Dr. Anne Moscona of Weill Medical College of Cornell University (New York, NY, USA), in an article on oseltamivir resistance in seasonal influenza, warned that personal stockpiling of the drug could lead to many people taking inadequate doses, for inadequate amounts of time, for an illness that may not even be influenza. All of these factors could contribute to the development of oseltamivir-resistant seasonal flu.

A third article addressed the question of whether doctors should prescribe oseltamivir on demand. A physician does not have an obligation to prescribe the drug, they argued, and from a public health point of view, they are actually obligated not to prescribe it, given the risk that haphazard use will lead to drug resistance.

"This year's run on oseltamivir should stimulate public health experts to consider more generally the dilemma encountered by physicians who have simultaneous obligations to individual patients and to public health,” stated Dr. Allan S. Brett of the University of South Carolina School of Medicine (Columbia, SC, USA) and Dr. Abigail Zuger of St. Luke's Roosevelt Hospital Center (New York, NY, USA), the authors of the article.