I've been taking a generic of Inderal -- Propranolol ER 80 mg cap 1x daily -- for irregular heart beat. Since I'm on Medicare, they will only let me take Metorprolol Tart 50 mg tab instead on the generic above. I'm concerned because I read the side effects of this drug and I don't believe the other drug has the same violent side effects...what can I do since I prefer to take the initial generic drug that I've been taking for years...