Stahl's Essential Psychopharmacology Online
In Collaboration With
Mannitol
Therapeutics
Brands
• Osmitrol
Generic?
• Yes
Class
• Osmotic diuretic
Commonly Prescribed for
(FDA approved in bold)
• Reduction of elevated intracranial pressure (ICP)
• Reduction of elevated intraocular pressure
• Diuresis (prophylaxis in acute renal failure)
• Increased excretion of urinary toxins
• Urologic irrigation
How the Drug Works
• Mannitol induces diuresis by elevating the osmolarity of the glomerular filtrate, which decreases tubular reabsorption of
water
How Long Until It Works
• 15 minutes
If It Works
• Assess effectiveness and need for continued use. Usually used as a short-term measure before more definitive treatment
If It Doesn't Work
• Usually mannitol is a temporary measure for acute increases in ICP before more definitive treatment
Best Augmenting Combos for Partial Response or Treatment-Resistance
• Treatment of increased ICP depends on the etiology
• Causes
of increased ICP due to general swelling include liver failure,
hypertensive encephalopathy, and hypercarbia. Intervention
should consist of treating the
underlying medical problem
• In some cases, meningitis can cause increased production of CSF or obstruction of CSF flow
• Increased ICP due to mass effect from stroke (ischemic or hemorrhagic), may require neurosurgical intervention such as an
intraventricular catheter, craniotomy, or craniectomy
• Permitting hypertension may increase perfusion and improve swelling, but calcium channel blockers may also be useful (especially
in subarachnoid hemorrhage)
• Analgesia and sedation may be useful
• Hyperventilation, hypothermia, and barbiturate coma are occasionally used, usually in refractory cases
• Hypertonic saline is an alternative to mannitol for acutely increased ICP
• Corticosteroids are often used to reduce vasogenic edema, i.e., brain tumors
Tests
• Carefully monitor serum sodium, potassium, BUN, and urine output during therapy