med_cat: (Default)
[personal profile] med_cat posting in [community profile] 1word1day
tachyphylaxis [tak′ēfəlak′sis]

1 (in pharmacology) a phenomenon in which the repeated administration of some drugs results in a rapidly appearing and marked decrease in effectiveness.
2 also called mithridatism. (in immunology), a rapidly developing immunity to a toxin because of previous exposure, such as from previous injection of small amounts of the toxin (named for Mithridates VI who used the technique to survive an assassination attempt).

Etymology: Gk, tachys, rapid + phylax, guard
Mosby's Medical Dictionary, 8th edition. © 2009, Elsevier.

Further re: meaning #1: this was a new word from my reading this week; it is the same phenomenon that's called "tolerance" with narcotics, when applied to non-narcotic substances, such as sedatives, neuromuscular blocking agents (i.e., paralytics, incl. curare derivatives), etc.

This account has disabled anonymous posting.
If you don't have an account you can create one now.
HTML doesn't work in the subject.
More info about formatting
Page generated Jun. 29th, 2025 04:55 pm
Powered by Dreamwidth Studios