I was just admitted to the hospital for Atrial fibrillation again, I have not had a problem with it for about 2 1/2 years I was taking 50mg of Atenolol. My cardiologist just stopped the atenolol and put me on the rythmol. My local pharmasist asked why he did this because the rythmol now costs me $50.00 a month, my doctor has me taking 1500mg. Why would he change from the atenolol when they seem to do the same thing, the atenolol only cost me $5.00 a month.