Some climbers use acetazolomide (Diamox) while climbing to help their bodies adjust while acclimatizing. Others may use it to help them sleep at night. It does have to be prescribed and some doctors have never heard of it. Some useful information can be found at the link beneath on this drug and there's a great deal of additional info you may want to read. You may also want to print off some of the info for your doctor if you plan on getting some.
A good rule of thumb to follow when first ascending above 10,000 feet is to average 1,000 feet per day. You may climb from 10,000 to 13,000 in one day and return to 10,000 to sleep. The following day move up to 13,000 and sleep. Then on the third day rest at 13,000. Three days, 3,000 feet.
Good luck and let us know how it turns out.