Flamenco guitarist Juan Martin deals with it by downing a glass of red wine minutes before stepping onto the stage and some artistes require bananas which contains some muscle-relaxation substances.
"I had discovered the stage fright drug Inderal, or propanolol, which blocks the receptor site for adrenaline. Unlike anxiety medication like Valium, Inderel lessens physical symptoms without affecting the brain. I'd gotten mine over the counter in Ecuador, but Inderel is best prescribed by a doctor. Too many sends people with low blood pressure or asthma into a tailspin. But at least my nerves wouldn't flare up."
-Blair Tindell in Mozart in the Jungle
I have noticed that quite a number of professional musicians who rely heavily on such drugs like Inderel for their career and at the same time, several people who have commented that musicians who requires such drugs shouldn't even be performing at all. Apparently some harsh and critical comments they have there. It does seem that they relate a musician's right to perform to whether they take the drugs or not. Aren't their inherent musicality and musical accomplishments sufficient to justify their place on the concert stage? It's a pity when one looks back in history and realises that the devil had struck the king of Bach, Glenn Gould, with severe performance anxiety which forced him away from the concert stage.
I personally am blessed with a mild performance anxiety. More often than not, it does escalate a little more than which I would prefer but bananas would usually solve the problem. I do find that a slight anxiety, when my body releases a slight rush of adrenaline, is helpful in performance. It really does help when I can switch into an altered state without much difficulty. Simply an deep analysis of the musical work away from my instrument would throw me into an altered state, whereby I'm oblivious of everything else including time which bounds the majority of entire human race. However, on important performance occasions, I do bring a small dosage of Inderel with me, just to be prepared for the sudden, uncontrolled surge in adrenaline that I might have. I have never felt a need to use it though as bananas usually do the job of eliminating the minute shivering of the fingers which can heavily cripple a guitarist when a slight misjudgment of the frets or strings can cause the entire piece to break down or snap me out of my altered state.
All in all, I do certainly wish that Inderel shouldn't be treated with disdain by those blessed ones who do not require it. Although I do not rely on it as my main remedy to curb those fight or flight response symptoms, I do recognise its importance to fellow musicians who are crippled without it. Not that I would encourage it, but it should be administered with a doctor's advice to those who are severely affected by nerves.