OC dick
As you get ready to run a train, the oxy contin (or any other painkiller) kicks in so hard that you cannot get a boner at all. Similar to whiskey/beer dick in that you are so fucked up that not a thing is gonna work. People experiencing OC dick generally experience frustration, dissappointment, and/or no nut.
Guy1: Yo I was tryin everything last night to get a boner, she was suckin my dick so good, but just couldn't cause of OC dick.
Guy2: Fuckin OC
Guy2: Fuckin OC