Respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract infection in infants and young children causing 125 000 hospitalizations per year in the United States. 1 In select groups of high risk infants appreciable morbidity and mortality still exists. 2 Ribavirin, a synthetic guanosine analog, was approved by the Food and Drug Administration (FDA) in 1986 for the treatment of RSV infection in high risk, severely ill infants. Ribavirin is administered during 12 to 18 h per day for 3 to 5 days as a continuous aerosol delivered via a small particle aerosol generator (SPAG) unit that generates particles with a median diameters of 1.0 to 1.3 m, enabling delivery of the drug down to the lower respiratory tract. The drug can be delivered through a tent or oxyhood system. Protocols for administering ribavirin in patients requiring mechanical ventilation are also available. 3

To date ribavirin has been administered to 127 000 infants since it was licensed with an excellent overall safety profile. Side effects reported have included nausea, headaches and rare exacerbations or worsening of bronchospasm with the initiation of aerosol therapy. Bronchospasm has been described in both babies exposed to the drug and caregivers who may be secondarily exposed to the aerosol. Rashes and conjunctivitis have been associated with ribavirin use, and these findings when they occur resolve within several hours of discontinuing the drug. Additionally the drug may precipitate on contact lenses so that they should not be worn during exposure to ribavirin. Anemia has been reported with systemic ribavirin administration. This has not been reported with aerosolized ribavirin, although it might require assessment 1 to 2 weeks after therapy to detect this change if it occurs. 4, 5 The major safety concerns related to ribavirin administration have centered on concerns related to potential teratogenicity for women of childbearing age (ie health care workers, mothers or visitors) with secondary exposure to aerosolized ribavirin. Although