I'd add the following tips I read about:
1. Drink more water than normal to compensate loss because lower atmospheric pressure, and because urination is higher, up to 0.5 litres extra/day.
2. Previous ingestion of some elemental iron (2 x 120 mg/day) with Vitamin C, 30 minutes before food or 60 minutes after them for better absortion. The more iron, the more red-cells, so more carriers for less oxigen from air.
3. Ingestion of liquid carbohydrates to compesate loss of appetite.
4. Ingest no salt or only small amounts to control hands and feet swelling.
5. Absolutelly NO heavy fats AND alcohol.
6. Protect against dehydratation through the skin.
7. If you're felling not good, consider riding to a lower site just to sleepping there. There is a rule about acclimatation that says : Climb high, sleep low.
In my case, I have been in Nevado del Ruiz, Colombia ( 4.800 + meters ) more than 30 times, but I learnt too late that drinking enough water to compesate dehidratation, was the clue for not having headache.
Enjoy the route, I'll see you in the road.