I have taken Synthroid for hypothyroidism for years, and six weeks ago my insurance company demanded that I switch to Levothyroxine. In the past I have had anaphylactic reactions to shellfish, salmon, wasp and bee stings and ammonia. Yesterday I had another anaphylactic reaction after eating blueberry pancakes, which I have eaten for years. An hour before that, however, I had taken a Levothyroxine and had felt strange about 10 minutes after I took the pill. It continued on, but I assumed it was just because I hadn t eaten anything yet. Is it possible that I could have had the reaction to the drug and not the food I ate?