I don't know if it's the niaspan or something else, but I've deve...

I don't know if it's the niaspan or something else, but I've developed a rash of all rashes from my neck to my legs. The itch is incredible and I've had it for four days now. I'm taking benedryl, but it makes me sleepy so I can't go to work. Anyone else had this problem? I just raised the dosage to the upper level from small and mid-range. I was on those 1 month each. I've now been on the high dosage for about two weeks. I stopped it two days ago. My CNP is out of town.......... YIKES! What do I do now?