INHALED ZANAMIVIR FOR THE PREVENTION OF INFLUENZA IN FAMILIES

Background As prophylaxis against influenza in families, amantadine and rimantadine have had inconsistent effectiveness, partly because of the transmission of drug-resistant variants from treated index patients. We performed a double-blind, placebo-controlled study of inhaled zanamivir for the treatment and prevention of influenza in families. Methods We enrolled families (with two to five members and at least one child who was five years of age or older) before the 1998–1999 influenza season. If an influenza-like illness developed in one member, the family was randomly assigned to receive either inhaled zanamivir or placebo. The family member with the index illness was treated with either 10 mg of inhaled zanamivir (163 subjects) or placebo (158) twice a day for 5 days, and the other family members received either 10 mg of zanamivir (414 subjects) or placebo (423) once a day as prophylaxis for 10 days. The primary end point was the proportion of families in which at least one household contact had sympto...