My doctor has prescribed 5 mg Crestor one day a week. I have had trouble with statin drugs in the past. I have many allergies to foods & preservatives -- they trigger a-fib. I started with 1/2 tablet for 2 weeks and the last 2 doses I have taken 5 mg -- both times I have had a-fib that night. My most severe allergies are to Nitrates & Nitrites, MSG & many related ingredients that contain processed free glutamic acid. I have a list of "hidden MSG" & am finding that has helped me to recognize the ingredients that trigger a-fib. I also react to antihistamines, Dextromethorphan HBR, Diphenhydramine HCI, Microzole Nitrate, Hydrolyzed gelatin, ferrous sulfate, Maltodextrin, Citric Acid, My question is whether some of the ingredients in Crestor may be related to my known allergies & if I should be continuing to try to make it work. The last time I took my weekly dose, I took it in 2 half tablet doses over two days -- the first day was not a problem, but after the second dose the next day I had a-fib again. Never mind!!!