I have a 10-hr transatl flight and am having horrible anticipatory anxiety. i have been prescribed xanax (alprazolam) and a betablocker. will they prevent a pa?

Possibly not: Xanax (alprazolam) would have to be given at a fairly high and constant dose to prevent a panic attack. The beta blocker will blunt peripheral symptoms of anxiety (rapid heart rate, palpitations, sweating, dry mouth, etc) but you might still feel anxiety. Ssri's are more reliable at preventing panic attacks.

Acupuncture.: Dr pappas provided an excellent response. I wanted to bring up a different possible solution for your 10 hour flight: acupuncture. Semi -permanent needles (asp) can remain in the ears for up to 7 days & are very effective for this purpose. I do this every time i fly. It doesn't cause grogginess & there are no med-med interactions.