Oseltamivir Resistance — Disabling Our Influenza Defenses

Abstract

As the potential for an influenza pandemic has galvanized the medical community and the public into action, physicians and patients alike have been heartened by the availability of effective antiviral drugs. The neuraminidase inhibitors provide valuable defenses against pandemic and seasonal influenza, and physicians have been flooded with requests from patients for personal supplies of oseltamivir (Tamiflu). A benefit of having oseltamivir at home is that the sooner the drug is taken after the onset of symptoms, the better its clinical efficacy.¹ And certainly, enabling ill people to stay home and out of waiting rooms and pharmacies should limit the spread of influenza. So it is not surprising that many believe there should be a supply of oseltamivir in every medicine cabinet. This scenario, however, is potentially dangerous. Misuse of the drug could rob us of the advantages that neuraminidase inhibitors provide, by favoring the emergence of oseltamivir-resistant influenza virus. The potentially serious consequences of oseltamivir resistance in patients with influenza A (H5N1) virus infections is alarmingly underscored by the report by de Jong and colleagues in this issue of the Journal (pages 2667–2672).