... on it he did not experience any side effects. He had a episode of atrial fib about a month ago and was restarted on the flecainide. For the past 3 weeks he has been experiencing muscle contractions, aches, weakness. He describes the muscle contractions as "drawing" and the contractions/spasms occur in different parts of his body. Our internist does not think it is the flecainide causing these symptoms since he didn't have trouble the 1st time. He thinks it might be a viral syndrome. Labs were all in normal range. My question is can you have side effects when you didn't have them before and does he need to contact the cardiologist