Abstract: In aspects, the invention provides a method of treating or preventing a nidovirus or picornavirus infection in a subject, the method comprising administering to a subject in need thereof an effective amount of an active agent of butamben, butylparaben, conivaptan, amphotericin B, pentoxyverine, lapatinib, vilazodone, imatinib (STI571), benztropine, raloxifene, solifenacin, retapamulin, bafetinib (INNO-406), imipramine, trimipramine, tolterodine, clomipramine, velpatasvir, cediranib (AZD2171), azelastine, desloratadine, nortriptyline, propafenone, mebeverine, elbasvir, cepharanthine, flupenthixol dihydrochloride, or a pharmaceutically acceptable salt thereof.

Abstract: A method for the treatment of a coronavirus infection, such as a SARS-CoV-2 infection causing coronavirus disease 2019 (COVID-19), in a subject in need thereof, which includes the administration of masitinib, or a pharmaceutically acceptable salt or solvate thereof. In addition, at least one further pharmaceutically active agent may also be administered.

Abstract: Provided is a method of treating a disease caused by a nidovirus that encodes Nsp15, such as a coronavirus, an arterivirus, or a torovirus, in a subject in need thereof comprising administering a therapeutically effective amount of an active agent selected from 3?-uridylic acid, 5?-uridylic acid, citrate, methacycline, meclocycline sulfosalicylate, mitoxantrone, epirubicin hydrochloride, daunorubicin hydrochloride, sorafenib, sunitinib malate, primaquine diphosphate, closantel, isopropyl ester of N4-hydroxycytidine, GpU dinucleotide or derivatives thereof, and tipiracil or N-substituted derivatives thereof. Further provided are a method of inhibiting an Nsp15 endoribonuclease of a nidovirus that encodes Nsp15 and compounds of formulas (I?) and (II?).