I’m not a MD but doctors are actually supposed to note literally everything they say to you or you say to them in the medical record as a way to CYA. In this case if you had an adverse reaction to taking the ivermectin (which does happen albeit rarely) she would have legal evidence that she told you not to and you couldn’t sue her for not warning you. Theoretically it also allows other care providers to see what has been discussed and what other treatments or medications a patient has been on that haven’t been prescribed. However in my experience doctors almost never read a patient’s medical history so that doesn’t happen.