Metoprolol
"After 8 hours of fast, irregular beating I went to the emergency room and was diagnosed with afib, which reverted on its own after a few hours. The doctor prescribed metoprolol ER 25mg. I tried to give this drug a chance, but it did absolutely nothing to stop subsequent episodes. If anything they seemed to get worse. It felt like my heart was stopping altogether. I'm a fit 27 year old with low BP and resting heart rate. Because of this, I have to question the doctor's judgement in prescribing this medication. It brought my BP and heart rate down even further, severely affecting my quality of life. I was constantly lightheaded, foggy, woke up with headaches, etc. Bad decision on his part. Switched to flecainide and feel like myself again!"