The explanation generally given is that the nerve and other cells become accustomed to the drug, so that they cease to react, or that an antitoxin is formed which antagonizes the poison, or that the poison is rapidly destroyed in the body.
Jacob antagonizes his sister by interrupting her while she's on the phone.
My neighbor antagonizes me by mowing his lawn at 6AM on the weekends.
I enjoy spending time with Susan, but Molly says she antagonizes the other members of our group.
Missing deadlines antagonizes my editor more than any grammatical error.