One thing you should think about is jet lag. Bring some headache medicine and something to help you sleep for the first couple nights at your destination. One of my jet lag symptoms is a severe headache the morning after my arrival. The last time I traveled to the Philippines from Texas, the jet lag triggered a migraine. I usually bring Ibuprofen and Benadryl as my jet lag medicines. I wouldn't recommend drinking any alcohol during your flight. Even if you feel tired during the day, try not to sleep until your usual bedtime. This will help adjust your body's internal clock. You might also have no appetite for the first couple days after your trip. Try to eat something anyway.
Another thing I've noticed is that if I do most of my travelling at night when travelling westward, and I arrive at my destination in the morning, there is little to no jet lag. If I leave Texas in the morning, and arrive in Manila in the evening, I get to look forward to 2-3 days of jet lag.
You probably will feel exhausted afterwards. It's hard to avoid that since you are changing time zones.
Unless your airline of choice has really good inflight entertainment, you might want to bring a CD
/FM radio, and some books to entertain yourself during this epic journey. Also, bring a good set of earplugs in case you want to sleep, and get a seat by the window. I've done a lot of long-haul flights in economy class, and I've found a window seat is the best place to sleep if you are in Sardine Class. You can lean up against the wall and, well.. at least, attempt to sleep.
I hope this helps, and I hope you have a good trip!