Most antiarrhythmic medications have several potential side effects, including cordarone. Coreg would not do all the same things that Cordarone does. Remember, the PDR lists any possible side effect that could occur, and thus is of limited relevance to an individual patient.
My husband has been taking cordarone for the past 2 years (for V-Tach) without any major side effects. He had been on sotalol, which he had a serious reaction to. Sotalol actually induced arrythmia in him. After 2 years on cordarone, things are good. It might be starting to affect his thyroid, though. In December, doctors will again check it to decide if he needs any thyroid med. I know it can affect the pulmonary system, but so far hasn't. At a local suport group meeting, we met a man who has been on cordarone for 10 years. Says it's the only med that has successfully worked for him, without major problems. So, it's not all bad...