Recommendations for the prevention and treatment of influenza using antiviral drugs based on cost-effectiveness.

Influenza is an acute respiratory disease that causes epidemics and pandemics in the human population of temperate regions. Influenza epidemics occur every year during the winter months, affecting approximately 10% of the population. The primary strategy for reducing the effect of influenza in the community is to vaccinate persons who are at risk or caring for high-risk individuals each year before seasonal increases in influenza virus circulation occur. Antiviral drugs can be used for the treatment of influenza and the prevention of seasonal and post-exposure influenza. Four antiviral drugs are available for the prevention and treatment of influenza infections: oseltamivir, zanamivir, rimantadine and amantadine. Antiviral drugs can be used for the treatment of influenza and for post-exposure and seasonal influenza prevention. The cost-effectiveness of antiviral therapies ranged from cost savings to more than US$130,000 per quality-adjusted life-year (QALY) for influenza treatment, from GB pound9000 to more than pound1 million per QALY for seasonal prevention and from cost savings to pound100,000 per QALY for post-exposure prevention. Based on the cost-effectiveness threshold of pound30,000 or $40,000 per QALY, antiviral therapies can be recommended for influenza treatment and post-exposure prevention in healthy and high-risk individuals and for seasonal prevention in high-risk individuals. Zanamivir, oseltamivir and amantadine have favorable cost-effectiveness ratios for these interventions, but amantadine should only be used in countries with a low prevalence of resistant virus. The stockpile of antiviral drugs should be maintained in developed countries because they are cost effective for the prevention and treatment of a possible influenza pandemic.