Place: another planet
People: Humans and one lone Time Lord.
Search Terms: debilitating poison, chronic poison, invalid poison (which got me lots of stories about suicides) debilitating drugs (hits on drug addictions and side effects),
I know I can make this up out of whole cloth and wrap it up with a bit of technical babble, but I would like to know what is possible in the here and now before I do.
I need a poison or drug that will make the victim seem an invalid. But not a disease or disorder. The villain is doing this to her and he needs her to be sick, not well and definitely not dead. So if you were trying to keep somebody sick in the present day in the first world, what would you use?
Then the Doctor and Martha need to cure her, but that's another question.