alexipharmic

alexipharmic \uh-lek-suh-FAHR-mik\, adjective:

1. Warding off poisoning or infection; antidotal; prophylactic.
2. An alexipharmic agent, especially an internal antidote.

True, I had lately given some attention to botanical studies; but my new knowledge extended only to the trees of the forest, and none of these with which I was acquainted possessed alexipharmic virtues. I knew nothing of the herbaceous plants, the milk-worts, the aristolochias, that would have served me.
-- Captain Thomas Mayne Reid, The Quadroon

That it is a poison most true,/ The worse, the deadlier the drought,/ The greater honor will be due/ To your alexipharmic craft./ Now, Doctor, you must show your skill;/ Whip them off clean, and make your will.
-- John Hall-Stevenson, Fables for Grown Gentlemen

Alexipharmic rose to prominence in the early Baroque period, from the Greek alexein, 'to avert' and pharmakon, meaning 'drug.' Alexipharmic was the dominant adjectival form until 'antidotal' overtook it in the 1640s.