The recent population explosion in anti-infectives seems to be almost entirely from antibacterial agents. Among the more meager nursery of antiviral agents is one that has recently been approved by the Food and Drug Administration (FDA) for respiratory syncytial virus (RSV). Ribavirin (1-β-D-ribofuranosyl-1,2,4-triazole-3-carboxamide) is a synthetic nucleoside analogue that may be heralding a new type of battle against the common respiratory ills of childhood. Ribavirin is of a different lineage; in vitro and in vivo it possesses inhibitory activity toward a wide range of both RNA and DNA viruses.1,2For respiratory infections in humans it appears to be most effective when administered as an aerosol, and toxic reactions have not been observed. Ribavirin bears a noticeable familial resemblance to guanosine and inosine. The mechanism by which it exerts its viral exorcism remains partially occult, but it does appear to specifically restrict the synthesis of viral proteins, in part by