Renal – Pharma

Intracranial pressure (ICP) rises in conditions such as head trauma, cerebral edema, or intracranial hemorrhage. The therapeutic goal is to reduce brain volume by removing excess water.

• Mannitol is an osmotic diuretic.

  • When given intravenously, it increases plasma osmolarity.

  • This creates an osmotic gradient that pulls water out of swollen brain tissue into the intravascular space.

  • The water is then excreted via the kidneys, thereby reducing intracranial pressure.

  • This makes it the drug of choice for acute management of elevated ICP.

Now, examining the incorrect options:

• Phenylephrine:
  An α₁-adrenergic agonist that increases blood pressure via vasoconstriction. It has no role in decreasing ICP; in fact, it may worsen cerebral perfusion issues.

• Midodrine:
  An α₁-agonist used to treat orthostatic hypotension. Again, it raises vascular tone, not useful for ICP reduction.

• Acetaminophen:
  An analgesic/antipyretic. It can lower fever (and thereby indirectly reduce cerebral metabolic demand), but it does not reduce ICP.

• Fludrocortisone:
  A mineralocorticoid used in Addison’s disease or orthostatic hypotension. It causes sodium and water retention, which could actually worsen intracranial pressure.

Thus, the drug that should be used to decrease intracranial pressure is Mannitol.