I took my first 500mg Niaspan ER at about 1130 after eating an ap...

I took my first 500mg Niaspan ER at about 1130 after eating an apple. At 0115 I woke up and my body from head to toe was on fire internally. I got up out of bed went to the bathroom looked in the mirror. It looked like I had a bad sunburn from head to toe plus my face,arms, hands upper torso were swollen. I do not recall any increase in my heartbeat. I went to the ER and by the the time the doctor came around I was some better. I did experience severe itching and cold chills for a while. I did not know about the aspirin for help. Am awaiting further directions from my cardiologist. I have never experienced anything like this before.