Description_x000D_ Biochem/physiol Actions_x000D_ MDL-860 is a 5-nitro-2-phenoxybenzonitrile that exerts broad-spectrum antipicornaviral activity (MIC50 from 0.1-1.5 μg/mL in HeLa cultures) by acting as an irreversible inhibitor against host phosphatidylinositol-4 kinase beta (PI4KB; PtdIns 4-kinase beta; PI4Kbeta; NPIK; PI4K92) via covalent modification of Cys646 located at the bottom of a surface pocket apart from the PI4KB active site. MCL-860 (MIC50 from 0.1-1.5 μg/mL in HeLa cultures). A pleconaril/MDL-860/oxoglaucine consecutive alternating administration (CAA), but not simultaneous daily treatment, is reported to be effective against coxsackievirus B1 infection without the development of drug resistance in newborn mice (75 mg/kg MDL-860 via s.c. every third day on the day following pleconaril and prior to oxoglaucine).