This Perspective article discusses the FDA’s emergency authorisation of peramivir, an investigational neuraminidase inhibitor in development for treatment of influenza. The FDA has the power to authorise unapproved drugs for use in the US where it is reasonable to believe that the drug may be effective in treatment of a condition causing a declared public health emergency. Peramivir is available in a parenteral formulation, and has been made available in the US to treat hospitalised patients with pandemic H1N1 influenza not responding to other therapies.

The authors summarise the clinical trial data so far available for peramivir, noting that only 1,891 subjects have received this drug in any dose and formulation, including 478 who have received a single IV dose and no children. On the available data, the drug seems to have a similar effect to other neuraminidase inhibitors, however there is inadequate information to be able to draw any conclusions about its efficacy. Prescribing the drug requires careful assessment of the limited safety and efficacy data available, and it is important to report any suspected adverse effects.

[Editor’s note: peramivir is not readily available, and there are only limited quantities for supply; the originator, a small US drug research company, has no UK or EU presence or development partner.]