Publisher Summary Thiazide diuretics produce metabolic changes including increased serum uric acid, decreased serum potassium, short-term increases in total cholesterol and low-density lipoprotein (LDL)-cholesterol, and long-term increases in triglycerides and insulin resistance. Diuretic-induced changes in potassium balance are not usually associated with appreciable effects on total body potassium stores. One year's treatment with hydrochlorothiazide 25–50 mg daily or altizide 15 mg plus spironolactone 25 mg one to two tablets daily was associated with reduction in plasma potassium of 0.35 or 0.19 mmol/1, respectively, but exchangeable potassium was unchanged. Exchangeable potassium increases slightly after hydrochlorothiazide. A research indicates that hydrochlorothiazide at an average dose of 44 mg daily increased plasma magnesium compared with doxazosin. In normal volunteers treated with hydrochlorothiazide 100 mg daily for one week, plasma magnesium was unchanged, but erythrocyte magnesium concentration was reduced. In many long-term trials, mean blood sugar is little affected by thiazide therapy.