For this reason you are playing with fire if you attempt to
pep-up the effects. It restricts bronchial dilation and it
doesn't mix well with other drugs. Never, ever mix it with
alcohol. 'Snorting' or inhaling propanolol may well be the last
thing you do.

Used occasionally on an as-needed basis you should be okay but
regular long term use can lead to severe lethargy and deep mood
swings, even diabetes. There is a safer alternative, Atenolol,
that also works as a beta-blocker. If you find symptom control
alleviates most of your anxiety you can achieve the same results
by learning a "relaxation response". It's not such a quick fix
but in time you can gain some control over your pulse rate and
the production of adrenalin, including blushing symptoms.