What does the "eighteen evils" in Chinese medicine mean? What does it mean?

My opinion on the incompatibility of traditional Chinese medicine. When the two drugs are used together, serious toxic reactions or side effects occur, which is called the opposite. According to the literature, there are 18 kinds of drugs: licorice, Daphne genkwa, kansui and seaweed; Radix Aconiti, Fructus Trichosanthis, Rhizoma Pinelliae, Radix Ampelopsis and Rhizoma Bletillae; Veratrum, Salvia Miltiorrhiza, Radix Adenophorae, Radix Sophorae Flavescentis, Radix Scrophulariae, Asari, and Radix Paeoniae (Scrophulariae is added to Compendium of Materia Medica, so there are 19 drugs). "Pearl Capsule Supplement": "Eighteen anti-tunes: Herbal Medicine contains eighteen anti-tunes, half of which attack Wu, algae halberd against grass, and all the participants are against Veratrum." This is the experience of the ancients and needs further study.