Board Thread:Versus Debates/@comment-43599250-20200323125032/@comment-32685487-20200324231047

Itachi never had reason to kill somebody with it in the manga/anime, and the effects that it had on Sasuke and Kakashi's brains and bodies were real so they had to be bedridden and in Sasuke's case he was in a coma. If Itachi did want to kill with it then its entirely possible and as you said he has done so in the novel.