diuretics

Question 1

mannitol - type of diuretic

Answer 1

osmotic diuretic

Question 2

mannitol - type of molecule

Answer 2

sugar alcohol; isomer of sorbitol

Question 3

mannitol - mechanism of action on kidneys

Answer 3

osmotic diuretic

• acts on descending LoH
• increases tubular fluid (filtrate) osmolarity –> decreasing reabsorption of water from tubule in descending LoH –> diluting urine and increasing urinary flow

Question 4

mannitol - mechanism of action on brain

Answer 4

osmotic diuretic

• shrinks/dehydrates cells
• decreasing intracranial volume
• releasing/opening tight jxns in BBB, allowing passage of molecules
• onset of action is 5 min after admin, lasts 30 min

Question 5

mannitol - toxicity

Answer 5

dehydration (excessive diuresis)

pulmonary edema

Question 6

mannitol - contraindications

Answer 6

anuria
CHF (increases intravascular volume)
active cerebral hemorrhage

Question 7

mannitol - clinical uses

Answer 7

cerebral edema - decrease intracranial pressure (ICP)
acute glaucoma - decreases intraocular pressure
Alzheimer’s & chemo for brain tumors - facilitation of drugs across BBB
drug overdose?
osmotic laxative - doses >20g