High ceiling/loop<unk> s High ceiling<unk> s may cause a substantial diuresis – up to 20% of the filtered load of NaCl (salt) and water. This is large in comparison to normal renal sodium reabsorption which leaves only about 0.4% of filtered sodium in the urine. Loop<unk> s have this ability, and are therefore often synonymous with high ceiling<unk> s. Loop<unk> s, such as furosemide, inhibit the body's ability to reabsorb sodium at the ascending loop in the nephron, which leads to an excretion of water in the urine, whereas water normally follows sodium back into the extracellular fluid. Other examples of high ceiling loop<unk> s include ethacrynic acid and torasemide. Thiazides Thiazide-type<unk> s such as hydrochlorothiazide act on the distal convoluted tubule and inhibit the sodium-chloride symporter leading to a retention of water in the urine, as water normally follows penetrating solutes. Frequent urination is due to the increased loss of water that has not been retained from the body as a result of a concomitant relationship with sodium loss from the convoluted tubule. The short-term anti-hypertensive action is based on the fact that thiazides decrease preload, decreasing blood pressure. On the other hand, the long-term effect is due to an unknown vasodilator effect that decreases blood pressure by decreasing resistance. Carbonic anhydrase inhibitors Carbonic anhydrase inhibitors inhibit the enzyme carbonic anhydrase which is found in the proximal convoluted tubule. This results in several effects including bicarbonate accumulation in the urine and decreased sodium absorption. Drugs in this class include acetazolamide and methazolamide. Potassium-sparing<unk> s These are<unk> s which do not promote the secretion of potassium into the urine; thus, potassium is retained and not lost as much as with other<unk> s. The term "potassium-sparing" refers to an effect rather than a mechanism or location; nonetheless, the term almost always refers to two specific classes that have their effect at similar locations: * Aldosterone antagonists: spironolactone, which is a competitive antagonist of aldosterone. Aldosterone normally adds sodium channels in the principal cells of the collecting duct and late distal tubule of the nephron. Spironolactone prevents aldosterone from entering the principal cells, preventing sodium reabsorption. Similar agents are eplerenone and potassium canreonate. * Epithelial sodium channel blockers: amiloride and triamterene. Calcium-sparing<unk> s The term "calcium-sparing<unk> " is sometimes used to identify agents that result in a relatively low rate of excretion of calcium. The reduced concentration of calcium in the urine can lead to an increased rate of calcium in serum. The sparing effect on calcium can be beneficial in hypocalcemia, or unwanted in hypercalcemia. The thiazides and potassium-sparing<unk> s are considered to be calcium-sparing<unk> s. * The thiazides cause a net decrease in calcium lost in urine. * The potassium-sparing<unk> s cause a net increase in calcium lost in urine, but the increase is much smaller than the increase associated with other<unk>  classes. By contrast, loop<unk> s promote a significant increase in calcium excretion. This can increase risk of reduced bone density. Osmotic<unk> s Osmotic<unk> s (e.g. mannitol) are substances that increase osmolarity but have limited tubular epithelial cell permeability. They work primarily by expanding extracellular fluid and plasma volume, therefore increasing blood flow to the kidney, particularly the peritubular capillaries. This reduces medullary osmolality and thus impairs the concentration of urine in the loop of Henle (which usually uses the high osmotic and solute gradient to transport solutes and water). Furthermore, the limited tubular epithelial cell permeability increases osmolality and thus water retention in the filtrate. It was previously believed that the primary mechanism of osmotic<unk> s such as mannitol is that they are filtered in the glomerulus, but cannot be reabsorbed. Thus their presence leads to an increase in the osmolarity of the filtrate and to maintain osmotic balance, water is retained in the urine. Glucose, like mannitol, is a sugar that can behave as an osmotic<unk> . Unlike mannitol, glucose is commonly found in the blood. However, in certain conditions, such as diabetes mellitus, the concentration of glucose in the blood (hyperglycemia) exceeds the maximum reabsorption capacity of the kidney. When this happens, glucose remains in the filtrate, leading to the osmotic retention of water in the urine. Glucosuria causes a loss of hypotonic water and Na+, leading to a hypertonic state with signs of volume depletion, such as dry mucosa, hypotension, tachycardia, and decreased turgor of the skin. Use of some drugs, especially stimulants, may also increase blood glucose and thus increase urination.. Low ceiling<unk> s The term "low ceiling<unk> " is used to indicate a<unk>  has a rapidly flattening dose effect curve (in contrast to "high ceiling", where the relationship is close to linear). Certain classes of<unk>  are in this category, such as the thiazides.
Diuretic
Antidiuretic
Uterotonic
Diuresis
Enuresis
Narcotic
Muscle relaxant
Natriuresis