I wouldn't take medication or drink much alcohol on the plane itself. I was once on a plane where there was a threat that proved to be false.

We disembarked and stood, then sat on buses for four hours while they searched the plane with dogs and removed the luggage. Then bus by bus we had to get off and stand in line then walk through rows of luggage and find our own. It was no place for sleepy people.

Back to the question, what worked for me on overseas trips: Depending on what time you arrive, if absolutely needed to keep you going that first day, take a 1-2 hour nap when you arrive. Be sure to set an alarm so you don't sleep too long. Warning: it's hard to wake up, but you really must force yourself.

That night take a benadryl at 7 p.m. and be in bed by 9. Have 1-2 cappucinos in the morning. You may have to repeat this cycle for a few days. As mentioned on a prior post, you should use it at home first to see how you react to it.

Good luck!