Hi - I was originally prescribed 60 mg/day - I was able to get away with 20 mg a day until I got PN - now its up to 40 - and I keep it close by all the time in case of tachy attack - and pop another 20 mg - which will usually stop the tachy in between 15 to 45 minutes.... the less med the better - that stuff keeps your heart from beating faster when it should - as you know - and also makes you dizzy when you stand up....