Hi my mum was currently on 3.75 mg bisipolol beta blockers and the doctor has suddenly told her to stop taking them I have had a look on the Internet and it's saying it could be dangerous? Is this right. She suffered heart attack in 2009 and was on 1.25mg up until she had 2 more heart attacks 24/12/2015 and also suffered a cardiac arrest. Now the doctor had suddenly stopped the bisiporol due to her pulse being low I am worried about her