I took two of those pain pills before going to bed last night, at about 12:30. I woke up about 9:30, and immediately had to run for the bathroom – I thought I was going to throw up, but I didn’t. I was nauseated and sweaty, so I went back to bed. And woke up at 1:30, still feeling a little nauseated and sweaty.
Googling for “ultracet side effects” shows that about 3% of people in the clinical trials reported nausea. So maybe it’s not the pills, but I don’t think I’m going to risk it.