There are several type of diuretics, chemical that enhance urinary output. An osmotic diuretic is a substance that is not reabsorbed and that carries water with it (for example, the high blood glucose levels of a diabetes mellitus patient). Alcohol, essentially a sedative, encourages diuresis by inhibiting release of antidiuretic hormone. Other diuretics increase urine flow by inhibiting Na+ reabsorption and the obligatory water reabsorption that normally follows. Examples include caffeine (found in coffee, tea and colas) and many drugs prescribed for hypertension or the edema of congestive heart failure. Common diuretics inhibit Na+ association symporters. “Loop diuretics” [like furosemide (Lasix)] are powerful because they inhibit formation of the medullary gradient by acting at the ascending limb of Henle’s loop. Thiazides are less potent and act at the distal convoluted tubules.