Pleconaril is an antiviral drug being developed by Schering-Plough for prevention of asthma exacerbations and common cold symptoms in asthmatic subjects exposed to picornavirus respiratory infections. Although the formulation used by Schering-Plough is a nasal spray, pleconaril is orally bioavailable, and is active against viruses in the Picornaviridae family, including Enterovirus and Rhinovirus. (en)
Pleconaril binds to a hydrophobic pocket in viral protein 1, the major protein which comprises the capsid (the outer "shell") of picornaviruses. In enteroviruses, this prevents the virus from exposing its RNA, and in rhinoviruses it also prevents the virus from attaching itself to the host cell. (en)