Could somebody familiar with common injections in hospitals and medicine and

[Erik C]

toxicity of medications.? Sorry for the vague question, my real question never would have fit up there.
I need to know what medications(in the form of an injection) that, when a dose slightly higher than prescribed, can be lethal for the patient. I'm thinking of things like potassium chloride or morphine(things that would be very common in any basic hospital, but could be very lethal in high doses).
Also, if you could give an example of a substance that could not be traced(easily) in the body after death, and if it brought about a gruesome form of death, that would be very interesting to know.

Don't worry, I'm not a psycho killer or anything, this is simply for the opening chapter of a novel I am trying to read, so don't get freaked out by my question.lol
Thanks.
Ooops, I just realized that my title question makes absolutely no sense. Oh well. sorry.

[top nurse]

you are right on with potassium
and arsenic or cyanide are hard to trace unless you know to look for it
BTW are you reading a Hannibal Lechter novel? those are really good

[HLD RN]

Any paralytics like Sucs or norcuron. They paralyze you. You stop breathing, but your still alive. In the hospital, whenever we paralyze someone we ALWAYS have to give a seditive with it or it would be cruel and unusal punishment to be paralyzed and suffocating cause you can't breath.(