Hypersensitivity as a result of drug abuse

Hmm....I had a friend that was on a ton of different meds to make things work right 'cause he abused drugs (bad) when he was younger & about OD'd so I don't know about that. Sounds plausible though....good luck with your search - sorry I couldn't help.

By hypersensitive you mean it takes less of the drug to get the same effect, as opposed to an allergy?

This does happen somewhat with alcohol as far as the observed result goes, but it's sort of an illusion, and a very poor prognostic sign. It is a result of extensive liver damage to the point that it takes less of the drug to overwhelm the surviving liver cells. They are most likely terminally ill by that point.

I've read that certain drugs (opiates) effect the beta-endorphins in the brain, which can make a person susceptible to relapse or sensitivity. Stimulant use hits your dopamine levels. Alcohol effects the brain's serotonin. Alcoholics have been shown to have much lower levels of serotonin than others. This brain chemistry is why "traditional" rehab fails. The person may get clean and sober, but the brain chemistry (neurotransmitters) have not been rewired so they're "itching" for a hit.

Radiant Recovery talks more about this, (there's an article about meth use) and might offer you some interesting insight into the brain's response. There's a lot of info about "upregulating" and "downregulating" your neurotransmitters, making you hyper-sensitive to the chemicals that hit your brain's "weak spot" (priming the pump).

try using the term "reverse tolerance" in your searching, and see if that helps.