Which is it: More hydration or less hydration? You can't have both.
I therefore see a number of fundamental inconsistencies in the thinking surrounding thiazides. Although the dangers of thiazide diuretics did not reveal themselves in the ALLHAT trial, they are there nonetheless.
In my experience, I have seen more harm done than good using these agents. While I cannot fully reconcile the reported benefit seen in ALLHAT with what I see in real life, all too often I see people having to take another drug to make up for a side-effect of a thiazide diuretic (e.g., high-dose prescription potassium to replace lost potassium, allopurinol to reduce uric acid, etc.). I have seen people require hospitalization, even suffer near-fatal or fatal events from extremely low potassium or magnesium levels.
My personal view: ALLHAT or no, avoid thiazide diuretics. Sure, it might save money on a population basis, but I suspect that the ALLHAT data are deeply misleading.
What's better than a thiazide, calcium blocker, or ACE inhibitor? How about vitamin D restoration, thyroid normalization, wheat elimination?