I took 800 mg ibuprofen for a headache and fell asleep, woke up 2 1/2 hours later forgetting that I took it, and I took a Tylenol PM.I usually take 800 mg Ibuprofen 3 x day for my arthritis and 5 mg Ambien at bedtime. My doctor has me on a 6 day regimen of 4 mg prednisone, which I started today...