Yes, be very cautious about taking too-high a dosage of Diamox. A woman just posted on the ladies of the JMT Facebook page that she suffered a seizure just below Mather Pass and had to be heli-evacuated out - doctors in Bishop suspect the electrolyte imbalance caused by her taking two 125-mg Diamox per day caused a heart "blip". I usually cut the 125-mg pill in half and take one per day (and I still get a bit of that annoying tingling).
I'd suggest calling your doctor and having him/her write a prescription for a lower dose.
