I had to quit Xyrem for many reasons, among which is that I started getting a motor tremor and my blood pressure rose from the 140/90 range to 180/105. I also developed a certain tolerance and had to move up to the highest end of the dosage range. Bottom line is that I chose to quit Xyrem. This stuff seems to produce different, and severe, side effects in a lot of people. It’s certainly not for everyone.