My husband was taking Prednisone and Benadryl for a particularly nasty case of Poison Ivy. He was on the short burst of Prednisone that taperd down over a week period. He was taking 50 mg of Benadryl at a time along with the steriod. About 4 days into this, he developed palpitations and a feeling of his heart pounding. Since he has never had this before, we went to the ER. He had an EKG, blood work and a chest x-ray. Everything was entirely normal. They mentioned that both drugs could cause this. My question is this, after two weeks, he is still getting small bouts of palpitations. Are the palpitations as a result of the drugs or just a coincidence? He DID drink large amounts of caffeinie in the form of soda, which he has cut way down. Does it take awhile for things to settle down after an incident like this? He does not smoke, nor drink, but could use to exercise more. Thanks for your help.