Final answer:
Diuretics, specifically osmotic diuretics like mannitol, are used to decrease intracranial pressure by moving fluid via osmosis, acting on the loop of Henle to inhibit Na+ and Cl- reabsorption.
Step-by-step explanation:
The drug treatment that helps to decrease intracranial pressure (ICP) by moving fluid via osmosis is a diuretic. Diuretics increase water loss by interfering with the recapture of solutes and water from the forming urine. Diuretics are drugs that increase urine volume by inhibiting the reabsorption of sodium (Na+) and chloride (Cl-) ions in the renal tubules, leading to increased excretion of water. A common type of diuretic for this purpose is an osmotic diuretic like mannitol which is often administered to reduce brain swelling following a head injury. By inhibiting the reabsorption of Na+ and Cl-, specifically in the loop of Henle within the kidneys, diuretics effectively increase urine volume and facilitate the movement of fluid from the brain to lower ICP.