I found your post on google searching for coq10 and what resembles a panic attack. I have taken coq10 for the last time as I type this. GNC brand coq10 200mg (started first taking it in 100mg doses 4th quarter 2015, then upped the dose to 200mg some time in December). Shortly after I take it my heart races to about 150 bpm even though I am standing still. Using the bathroom frequently but not diarrhea, slight chest pains when breathing in deeply (somtimes), lumpy throat feeling, frequent leg and hand/arm shaking, and what feels like acid in the throat. I have went to the ER twice in the last month or so, the first time with abdominal pain, tachycardia and lactic acidosis. Second time I thought fish allergy but with no hives or itching. I went to many doctors over the last month and unable to narrow the problem down. Last night coming home with the idea that I have a fish allergy I presumed to take the coq10 after eating a chicken and broccoli dinner. Shortly after and continuing as I type now all the symptoms are back, I am about 7-8 hours into the episode. Tried drinking chamomile tea, it is helping the shakiness a bit and bringing the hear rate down but i'm still not 100%, I am drinking water, ate an orange and a glass of milk to try and move it through my system quicker. It's a very un- settling feeling, I am not sure why I am experiencing this and many others including my girlfriend seem to have no problem tolerating coq10. Any help would be appreciated