Oseltamivir: finding a place in the influenza treatment arena

Controversy has surrounded the use of oseltamivir for the treatment of influenza since its recent launch in several countries, including the US and Switzerland. This is in part due to the narrow prescribing window (≤ 2 days from the onset of symptoms) during which oseltamivir must be administered in order to be effective. Sceptics are also quick to point out that, at maximum efficacy, this neuraminidase inhibitor reduces symptom duration by only 1.5 days, compared with placebo. Those in favour of oseltamivir argue that there are limitations in relying solely on vaccines to manage influenza and that the M2 inhibitors, amantadine and rimantidine, are not active against influenza B and are associated with CNS and gastrointestinal toxicity. Drawbacks also exist with the only other neuraminidase inhibitor available, zanamivir. This agent has very low oral absorption and therefore must be administered via inhalation. Experts attending the 10th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) [Stockholm, Sweden; May 2000] agreed that an influenza pandemic is imminent and thus, having a number of treatment options is essential. Even outside a pandemic period, influenza places a large burden on societal health resources. As a new drug then, what place does oseltamivir have in the treatment arena of this disease?