Re; the lidoderm patches stay on much better if you use a little rubbing alcohol or tea tree antiseptic cleanser on the area first. I just put some in a spray bottle so that I don't have to rub it on and then let it air dry for a minute before applying the patch.

The compounded cream can also be formulated with Ketamine so you may also want to ask about that formula. Personally I have found that the effectiveness of either the compounded cream and the lidoderm works better with continued use so hopefully you can get some at least a few days before your flight.

Are you traveling into the US? If you are then I would also suggest going through looking for the line that handles persons with disabilities, it will require you to have additional screening but, at least in my experience, it is much easier than being pulled aside for same. Bonus.. that it usually has a much smaller line. It has also been my experience to have an easier time coming into the states (if that is your destination) than it is leaving.

Wishing you the best!