Osmotic diuretic

Osmotic diuretics (also: osmodiuretics ) are high molecular weight substances, ie those with a high molecular weight that are filtered freely in the glomerulus of the kidney, in the further course of the renal tubule, however, can not be reabsorbed. This means that they retain water osmotically in the urine, which would normally have been reabsorbed from the primary again.

Because of their high molecular mass can not be absorbed by the intestines osmotic diuretics generally and must therefore be administered parenterally.

Representative

• Mannitol ( mannitol infusion ®, Osmofundin ®)
• Sorbitol ( Sorbitol Solution for infusion ®)

As another example of an osmotic diuretic may be mentioned the glucose (dextrose ). For diabetics it comes from a certain level of blood sugar level to a transfer of glucose in the urine when the filtration capacity of the renal tubules is exhausted. This triggers an increased urine flow as sugar binds water osmotically. This fact has also given its name to the diabetes: Diabetes mellitus is called in German " honey- sweet flow ".

The same applies to elevated serum concentrations of urea in protein-rich diet and bicarbonate for stays in height.

Example of use

Mannitol is used for example for the treatment of cerebral edema. Here, a hypertonic solution of the active agent is administered intravenously infused, so that the excess water can flow away to the osmotic pressure following and as a result lowers the intracranial pressure at the affected site.