Zanamivir for the prevention of influenza in adults and children age 5 years and older

On a yearly basis there are 3–5 million severe cases and 250,000–500,000 deaths worldwide attributed to influenza. Four antiviral medications are currently available on the market; however, resistance has resulted in the armamentarium being shrunk to two remaining active treatment options for influenza. These two neuraminidase inhibitors, oseltamivir and zanamivir, are recommended for the treatment and prophylaxis of influenza A and B in children and adults. Zanamivir, which is the focus of this review, is an inhaled antiviral that has shown benefit in the community, household, and nursing home population for post-exposure prophylaxis. Zanamivir protection rates range from 67%–84% in clinical trials of adults and children. Although the influenza vaccine remains the best modality to combat the disease, zanamivir may also assist in decreasing morbidity associated with influenza A and B.