I've been on pain management for over 15 years for a botched knee replacement. I've been taking morphine sulfate ER 20 mg 3x a day and oxycodone 20 mg when needed (sometimes as little as once in a 12 hour period but unfortunately as often as 4 times in a 24 hour period). I got my meds in a different part of town this time around and have found that I have been feeling very stoned (a feeling I don't like at all). Why would I be feeling this way all of a sudden? Sometimes I feel like I have too much blood in my head, resulting in a massive headache. Besides not taking the medication (which I have done in the past when I've had days with less pain) what can I do to alleviate this feeling? I also have found that sometimes after taking one of these pills, I've felt very hostile. I really don't like the feeling I get with this medication and I will discuss it with my Dr. at my next visit but in the mean time, should I be concerned? What can I do? Thanks so much for your answer.