Oseltamivir Resistance Seen in Two Avian Flu Deaths
Vietnamese patients treated with Tamiflu died of resistant influenza A (H5N1) virus
WEDNESDAY, Dec. 21 (HealthDay News) -- Two of eight Vietnamese patients treated with oseltamivir (Tamiflu) died of avian flu earlier this year after the influenza A (H5N1) virus developed high-level resistance to the drug, according to a report published in the Dec. 22 issue of the New England Journal of Medicine.
Menno D. de Jong, M.D., Ph.D., of the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam, and colleagues describe the case of a 13-year-old Vietnamese girl who died of avian flu last Jan. 28 after being treated with oseltamivir. The girl's mother died of the illness Jan. 21, also after being treated with oseltamivir.
Analysis of a throat swab on the fourth day of the girl's oseltamivir treatment revealed changes in the chemical composition of the virus and high-level resistance to oseltamivir, the researchers found.
"At least in some patients with influenza A (H5N1) virus infection, treatment with the recommended dose of oseltamivir incompletely suppresses viral replication. Besides allowing the infection to proceed, such incomplete suppression provides opportunities for drug resistance to develop," the authors write.
An accompanying editorial warns that "misuse of the drug could rob us of the advantages that neuraminidase inhibitors provide, by favoring the emergence of oseltamivir-resistant influenza virus."