be doped to the gills

To be thoroughly intoxicated by drugs, especially those prescribed by a doctor, to the point of incoherence or senselessness. I was doped to the gills for about two weeks after my surgery. I'm off the painkillers now, but I still feel pretty out of it. Boy, you were doped to the gills after your procedure. You said something about "purple moon sprinkles" and then couldn't stop laughing. You can't drive while you're taking these medications—you're doped to the gills!