Mithridatism

The word is derived from Mithridates VI, the king of Pontus, who so feared being poisoned that he regularly ingested small doses, aiming to develop immunity.

[1] After this, Mithridates VI's mother held regency over Pontus (a Hellenistic kingdom, 281 BC–62 AD) until a male heir came of age.

He then began to notice pains in his stomach during his meals and suspected his mother had ordered small amounts of poison to be added to his food to slowly kill him off.

In keeping with most medical practices of his era, Mithridates' anti-poison routines included a religious component, supervised by the Agari, a group of Scythian shamans who never left him.

It was believed that engaging in sexual activities with vishakanyas could result in the death of their partners, due to the exchange of poisonous body fluids.

Chanakya entered the room at the moment she collapsed, and in order to save the child in the womb, he immediately cut open the dead queen's belly and took the baby out.

He was just in time; a drop of poison had already reached the baby and touched his head, leaving a permanent blueish spot (a "bindu") on his forehead.

[13] Mithridatism has been used as a plot device in fiction and on-screen; including the Indian fantasy series Chandrakanta, Alexandre Dumas's The Count of Monte Cristo, Holly Black's "The Cruel Prince", Nathaniel Hawthorne's "Rappaccini's Daughter", Yoshiaki Kawajiri's Ninja Scroll, Dorothy Sayers's Strong Poison, Agatha Christie's Curtain, the manhwa Roxana, the manga/anime Spy x Family, the manga/anime/light novel series The Apothecary Diaries, William Goldman's The Princess Bride (as well as its film adaptation), and the American historical series The Borgias.

A. E. Housman's "Terence, this is stupid stuff" (originally published in A Shropshire Lad) invokes mithridatism as a metaphor for the benefit that serious poetry brings to the reader.