r&l,   Thanks for your question.   Though I can say with any certainty what your problem is, it sounds like your pain is directed related to taking your medication, which makes me wonder if there is a problem in the esophagus.  Of course other sources need to be checked out also.   If you are pain free, I would call your doctor for an appointment as soon as possible so that he/she may evaluate you with further questions about your symptoms, an examination, and an electrocardiogram.  He will then be in a better position to determine what the problem might be, as well as develop a plan to evaluate you further, if necessary.   Should this pain occur again, I would go to the emergency room for an acute evaluation.   Best wishes.   Martin Cane, M.D.