are doing, going off the Propanolol is riskier than staying on it. It not only keeps your
blood pressure and heart rate lower, but it keeps you from having the effects of a thyroid storm (a malignant acceleration of heart rate, blood pressure, and body temp that can result in brain damage, a heart attack, or a stroke).
Also, when the time comes for you to go off of it, you should taper over a 2-4 week period. (Eg. Week one-take 1/2 dose each day; Week #2 take 1/2 dose every other day, etc.