An average episode good enough to watch but not an episode I would re-watch again.
I saw this episode a bit differently. For me this episode was how money DOES NOT change certain people. In this case, the family in this episode are still pretty miserable and unloving. Well actually just the Dad the Mom is super great and she doesn't deserve what she gets in the end.
The kid in this episode is annoying at times and his reaction at the end toward both his parents (when it should have been just his dad) is a bit too much.
I did feel like the mom deserved to win the lottery, she's the only that seems capable of loving and tolerating people. The twist about the "smart pill" seems to be a double edge sword. In this case, it serves an evil purpose which is revenge. It also kills the uncle so the "pill" itself is not very healthy. It demands too much of those who use it and there is no guarantee that what people do with the knowledge they get they will use for the better.
So while the "Bitterest Pill" is the title, it could have easily been changed to "The Bad Pill" or "Too much knowledge can be bad".