... mistake in prescribing Metoprolol Succinate ER, 100 mg each tab 2x per day,morning and evening. He thinks it should be ix a day as it is in fact the ER form. Of course I have put a call into him and am awaiting his response. What do you think? Note that I do have for years COPD and my breathin seems to have gotten worse over time.I was prescribed the Metoprlol due to periodic rhythem irregularities, which have totally gone away. I just wondering if I really need all this stuff I'm on. Your thoughts?