The Wrong Bottle.

In "The Wrong Bottle", Tom is annoyed since his freeloading brother-in-law lives with them and he's quite thoughtless. After some arguing, the brother-in-law informs Tom that his insurance policy has lapsed....and soon after this Tom thinks he's accidentally drank poison. However, when he heads to the store to buy some antidote, he's frustrated by a dopey druggist and other store employees....and there's more craziness after this.