Unbelievable. I was on 25mg (mind you 25mg) of toprol
XL for several years until the cardiologist said: "That is bad stuff, get rid of it". Per his instructions, I cut
the pills in half and took those for 10 days and then took the now 12.5 mg every other day for another 10 days. I had no ill effects. I can't, obviously, comment on your condition but 300mg of that stuff every day is frightening to me.