From the Guidelines
Mannitol is not recommended as a first-line treatment for hypertensive emergencies. Instead, intravenous antihypertensive medications like labetalol (initial dose 20mg IV, followed by 20-80mg every 10 minutes as needed), nicardipine (initial rate 5mg/hr, titrated by 2.5mg/hr every 5-15 minutes, maximum 15mg/hr), or clevidipine (starting at 1-2mg/hr, doubling every 90 seconds until near target BP) should be used to gradually lower blood pressure 1.
Key Considerations
- Mannitol, an osmotic diuretic given at 0.25-2g/kg IV over 30-60 minutes, is primarily indicated for reducing intracranial pressure in cases of cerebral edema that may accompany hypertensive encephalopathy 1.
- It works by drawing fluid from brain tissue into the vascular space through an osmotic gradient.
- However, mannitol alone doesn't directly address the underlying cause of hypertensive crisis and may cause fluid shifts, electrolyte abnormalities, and renal dysfunction.
- For hypertensive emergencies, the goal is controlled blood pressure reduction (typically by 25% in the first hour) using medications that directly affect vascular tone and cardiac output, while carefully monitoring for end-organ damage 1.
Preferred Treatment Options
- Labetalol, nicardipine, or clevidipine are preferred for their ability to be titrated and their direct effect on vascular tone and cardiac output.
- The choice of medication should be guided by the presence of comorbidities and the specific clinical scenario, as outlined in the guidelines 1.
From the FDA Drug Label
MANNITOL injection, for intravenous use Initial U. S. Approval: 1964 INDICATIONS AND USAGE Mannitol Injection is indicated for the following purposes in adults and pediatric patients. Therapeutic Use Reduction of intracranial pressure and brain mass. ( 1) Reduction of high intraocular pressure. ( 1) Diagnostic Use Measurement of glomerular filtration rate. ( 1)
The FDA drug label does not answer the question about the use of mannitol in hypertensive emergency.
From the Research
Hypertensive Emergency Treatment
- The primary goal of intervention in a hypertensive crisis is to safely reduce blood pressure 2.
- Patients with hypertensive emergencies are best treated in an intensive care unit with titratable, intravenous, hypotensive agents 2.
- Rapid-acting intravenous antihypertensive agents are available, including labetalol, esmolol, fenoldopam, nicardipine, and sodium nitroprusside 2, 3.
Available Agents
- Newer agents, such as clevidipine and fenoldopam, may hold considerable advantages over other available agents in the management of hypertensive crises 2, 4.
- Clevidipine is now endorsed by guidelines as a first-line treatment option for blood pressure reduction in acute ischemic stroke and may be considered for use in intracranial hemorrhage 5.
- Sodium nitroprusside is an extremely toxic drug and its use in the treatment of hypertensive emergencies should be avoided 2.
- Nifedipine, nitroglycerin, and hydralazine should not be considered first-line therapies in the management of hypertensive crises because these agents are associated with significant toxicities and/or adverse effects 2, 4.