Beta blockers such as these have been used for decades to manage anxiety. A London orchestra - I think the LPO but may be mistaken - all took them for a year. Their reviews crashed. The problem is that they reduce performance. People become lethargic and less concerned about excellence. If you take them on the flight deck IMHO you are a danger..
Of course the same drugs are used for hypertension, but only under prescription. Taking them for anxiety IMHO is wrong. Moreover if you take them you will have to declare this to your AME who may well tell you to come back at a later date once they have cleared your body. Failure to declare you have taken them is a serious offence and not only risks loss of your license but also potential prosecution.
Most AMEs are well aware and can cope wi white coat syndrome. Just be honest