Level 3

↓ICP/IOP

Usually rare and idosyncratic. It may cause symptoms of pulmonary hypertension.

IV only.

Biphasic – plasma and ECF.
Does not cross BBB

0.47 L/kg

Urine (~55% to 87% as unchanged drug)

Term half life: 4.7 hrs

1-2gm/kg IV

Osm (20%) 1100

ADVANTAGES:
Still fairly cheap
• Rapid effect (onset – minutes, duration – 3
hrs)
• Seems to have some sort of rheological
benefit (increases red cell deformability)
• Acts as a transient volume expander
• May have a better effect on cerebral blood
flow for a given reduction in ICP.

DISADVANTAGES:
Unstable in storage: at low temperatures
and at altitude, it precipitates.
• Medium for bacteria and fungus.
• Causes a brief state of volume overload
• Causes torrential diuresis and hypovolemia
• Causes hyponatremia while in the serum,
and hypernatremia after the inevitable
diuresis
• washes out medullary interstitial gradient -
> decreased ability to concentrate urine
• Endpoint is serum osmolality(320), which is
cumbersome to measure
• May cause ICP to "rebound" after
prolonged use
• should be discontinued if Na+ > 160 or
osmolarity > 320mosmol/kg

Diuretic - Osmotic

polyhydric alcohol MW 200, synthesized by redn of mannose

osmotic diuretic
(to ↓intracranial pressure or introccular pressure).
Used to test for airway hyperresponsiveness

1-% or 20% (100gm in 1000ml or 500ml)
Crystallizes at ↓temp

osmotic agent. inc plasma osmolality and draws water out of the CSF and vitreous body. Freely fi¬ltered at the glomerulus but poorly reabsorbed. Because
the PCT is involved in the reabsorption of 60-70% of the -filtered load
this is the most important site of action

Minimally hepatic to glycogen

Osmotic Diuretic

an alcohol derived from Dahila tubers (6 carbon
sugar)

decrease ICP: 0.25g/kg over 15min to 1g/kg

PROS & CONS – See BELOW

1. reduce CSF volume -> reduce ICP
2. preserve renal function during perioperative
period in jaundice patients under going major
vascular surgery.
3. acute management of glaucoma
4. bowel prep
5. initiate diuresis in transplanted kidney
6. treatment for rhabdomyolysis

sterile solution
10-20% in water

• increases the osmolarity of the glomerular
filtrate -> increasing urinary volume
• decreases CSF volume & pressure by
(1) decreasing rate of CSF production
(2) withdrawing brain extracellular water across
the BBB into plasma

Unmetabolized