The solution to one's feeling glum about an ex lover, by hooking up with someone else to take his(/her) mind off of it.
An "antidote" in the form of another's "panties."
Man 1: I'm so upset over Angela, I don't know what I'll do!
Man 2: Well that sucks, but Jen is looking pretty cute tonight. She may be the pantidote you're looking for!