I am having a lot of gastric distress (heartburn, bloating, gas) with this drug, also some muscle pain and skipped beats yet. I am taking 100 mg. cr morning and 100 mg. at night. This is half the dose I was prescribed, but I am very sensitive and wanted to start out slowly. Now I am afraid to increase the dose. I am scheduled to be put on a 30 day event monitor in 3 days, after having been on it a week. Any suggestions? I am taking it for persistent Afib.