... propranolol for STV. Disopyramide is becoming very hard to get now so I have been changed to diltiazem (Adizem 2 x 120mg slow release capsules) starting today. I have had to stop propranolol for twenty four hours before this change of drug. And disopyramide last one yesterday. I am feeling quite ill and would appreciate any advice as to how long this feeling of terrible anxiety and pounding heart will last before this drug starts to work - having had control of STV for so many years I feel like I have turned back 40 years - or is it just withdrawal from these drugs that have been my life line for years. Appreciate any advice