Use with caution is pts that are likely to be susceptible to volume contraction from excessive diuresis, i.e. hypertension treatment in elderly with little or no edema. Caution in pts susceptible to hypokalemia, i.e. digitalis administration, hepatic cirrhosis. These compounds then are relatively ineffective in renal insufficiency . Thiazides can induce a volume contraction, which leads to enhanced proximal tubule reabsorption of fluid and solutes. All are well absorbed from the gut.
Onset of action is within approx.
Metolazone is a quinazoline diuretic that has the same sites of action and side effects as the thiazides. It is the only distal nephron diuretic that can be efficacious in pts with sever renal insufficiency and is often given in combination with a loop diuretic. Collecting duct diuretics Potassium sparing diuretics These agents are often given to avoid the hypokalemia that accompanies the agents previously described. They should never be given in the setting of hyperkalemia or in pts on drugs or with disease states likely to cause hyperkalemia. These include diabetes mellitus, multiple myeloma, tubulointerstitial renal disease, and renal insufficiency.