Mannitol

Question 1

What are the trade names for Mannitol?

Answer 1

Osmitrol, Resectisol

Question 2

What is the formal drug classification of Mannitol?

Answer 2

Osmotic Diuretic

6-Carbon Sugar

Question 3

What are the clinical uses of Mannitol (5)?

Answer 3

• reduces increased ICP associated with cerebral edema
• Prevention, differential diagnosis and treatment of oliguria/anuria
• Reduces IOP
• Promotes urinary excretion of toxic substances (ie radio-contrast dye)
• GU irrigant in transurethral prostatic resection

Question 4

What is the MOA of Mannitol?

Answer 4

Increases the osmolarity of the plasma, glomerular filtrate, and renal tubular fluid

• this promotes the movement of intracellular and extracellular fluid into the plasma and out of such places such as brain tissue. This will temporarily increase plasma volume
• Eventually, diuresis will occur as a result of the fact mannitol is filtered but NOT reabsorbed from renal tubules.
• also promotes flow to the renal medulla and is an oxygen free radical scavenger

Question 5

Is mannitol reabsorbed? Explain!

Answer 5

NO! It is filtered but NOT reabsorbed from renal tubules

-as the mannitol is filtered, it draws fluid and electrolytes such as sodium, chloride, and bicarbonate into the urine

Question 6

What is the ultimate effect of Mannitol?

Answer 6

INCREASED urine output

Question 7

What is the onset of action of Mannitol?

Answer 7

15 minutes

Question 8

What is the DOA of Mannitol?

Answer 8

3-6 hours

Question 9

How is mannitol metabolized and eliminated?

Answer 9

NOT metabolized; eliminated unchanged in the urine- only means of clearance= Glomerular Filtration

Question 10

What is the Volume of Distribution of Mannitol?

Answer 10

Remains confined to extracellular space (except in extreme concentrations) does NOT penetrate blood brain barrier

Question 11

What is the half life of Mannitol?

Answer 11

1.1 - 1.6 hours

Question 12

What are the side effects of Mannitol?

Answer 12

• Headache
• Convulsions
• Rash
• N/V
• Blurred Vision
• Polyuria
• dysuria
• acute and dramatic increase in intravascular fluid volume, pulmonary edema in patients with oliguria secondary to cardiac failure or in those with poor baseline myocardial function

Question 13

What can prolonged use of Mannitol cause?

Answer 13

Hypovolemia
Electrolyte Imbalance
Plasma Hyperosmolarity

Question 14

What are the contraindications to the use of Mannitol?

Answer 14

• Hypersensitvity to mannitol or any component of the formula
• Severe renal disease
• Dehydration
• Active Intracranial Bleeding
• Severe pulmonary Edema or congestion
• Severe myocardial dysfunction (unable to handle rapid expansion of intravascular volume)

Question 15

What should you establish first before administering mannitol?

Answer 15

Renal and Myocardial function! Give test dose

Question 16

What is the drug interaction with Mannitol?

Answer 16

Lithium Toxicity!!!! (with diuretic induced hyponatremia)

Question 17

What is the dosage of Mannitol?

Answer 17

0.25 - 1 g/kg IV over 30-60 minutes

Question 18

When should you administer Mannitol in an in line 5-micron filter set

Answer 18

with concentrations > than 20%

Question 19

Do not adminster _________-___________ mannitol solution with blood

Answer 19

electrolyte-free