Management of influenza - Use of new antivirals and resistance in perspective

In most years epidemics of influenza cause a significant increase in morbidity and mortality worldwide. With the availability of a new class of antivirals targeting the viral protein neuraminidase, there are new options for the control of influenza. The use of the older antiviral agents (M2 inhibitors: amantadine and rimantadine) is limited because of lack of activity against influenza B viruses, unfavourable tolerability in the case of amantadine and rapid emergence of resistance in a substantial proportion of treated persons, Neuraminidase inhibitors (NAIs) are potent and selective drugs that inhibit influenza neuraminidase, an enzyme that promotes the release of influenza virus from infected cells and facilitates virus spread within the respiratory tract. In contrast to the M2 inhibitors, NAIs have broader anti-influenza activity, better tolerance than amantadine and the frequency of resistance emergence is expected to be lower based on the lower incidence of resistant isolates emerging during the clinical trials. NAIs provide an important new option for the treatment of influenza and will play an important role in its management. Although the current data on viral resistance are very reassuring, it will be important to continue to monitor the broad use of NAIs in general practice. Therefore, collaborative virological surveillance systems have been set up to monitor the use of NAIs in clinical practice.