What Are The Side Effects Of Multaq?

I was on coumadin for several years. I had stomach bleeding, maybe ulcer and was given 8 units of blood plus 3 units of platlets and 2 units of plasma. I can no longer take coumadin thus took Digoxin for Atrial Fib. I am having atrail fib much more often and the dr. wants me to take multag. I am concerned about new meds and especially with respects to liver. Can you give me the good side and bad side of taking multag. I am 69 years old, am a diabetic but it is under control after bariatric surgery. Also had aortic valve replaced and have a placemaker. I am also on Lopresser twice a day.