My panic attacks can be triggered by reactions to specific events and or dietary conflicts. Sometimes, I swallow too much air when I eat, other times incomplete digestion creates a build up of gas, which will lodge in my GI tract. This tends to cause uneasiness and sometimes full on panic.
I have had great success with taking simple calcium based anti acids like TUMS.
Supplement wise I would avoid any thing that follows the adrenigenic pathways( caffiene, effedrine, most OTC stims). I really like AL-carnitine, it is very effective for, both relieving anxiety and promoting clear thought patterns. It seems to enhance my cardio-performance. I also like sulbutiamine and idebenone for a clean alert strong well being type of feeling. I don't know if this stack burns fat as effectively as an ECA stack, but It prevents that tired depressed feeling I get from dieting. Good luck!