Mannitol 20% solution is given 0.5 to 1 g / kg IV (2.5 to 5 mL / kg) over 15 to 30 minutes and repeated in a dose ranging from 0.25 to 0.5 g / kg (1.25 to 2.5 mL / kg) given as often as needed (usually every 6 to 8 hours); it lowers ICP for a few hours.