A deuterated nitrogen-containing heterocyclic carboxamide deriveative represented by the general formula or a salt thereof: [wherein D denotes a deuterium atom R denotes a hydrogen atom or a deuterium atom] exhibits excellent pharmacokinetics and the like, such as the maintenance of a high blood concentration and/or the increase of an AUC, and is hence useful as an antiviral agent.一種由下列通式所代表的氘化含氮雜環羧醯胺衍生物或其鹽類:[其中,D表示氘原子;R表示氫原子或氘原子]其展現絕佳的藥物動力學等,例如維持高血液濃度及/或具有增加的AUC,因此可用作為抗病毒劑。
