Thanks to my Dutch friends (who gave me quad strength pills without warning me), I overdosed badly (by a factor of 4) on ibuprofen a few years ago. I got horribly hot and sweaty and came out with lumps all over my face and back, they itched like mad.
The paramedic who took a look at me told me not to do it again, and that I'd be OK in a couple of hours. He was right.