From the Guidelines
For patients with pheochromocytoma, alpha-blockers such as doxazosin or terazosin are the recommended first-line blood pressure medications, as they effectively control blood pressure and adrenergic crises. According to the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1, administering doxazosin or terazosin, followed by a beta-blocker, usually controls BP and adrenergic crises. The guidelines also suggest that labetalol, which has alpha-blocker properties, can be used to treat adrenergic crises, especially when given intravenously.
Some key points to consider when managing blood pressure in patients with pheochromocytoma include:
- Starting alpha-blockers 7-14 days before surgery to control blood pressure and prevent hypertensive crisis
- Using beta-blockers like propranolol or metoprolol only after adequate alpha-blockade has been established, as using beta-blockers alone can worsen hypertension
- Avoiding medications that can trigger catecholamine release, such as certain antidepressants, decongestants, and stimulants
- Carefully managing fluid administration to prevent profound hypotension, particularly right after tumour excision, as patients with pheochromocytoma often have peripheral hypovolaemia.
It's also important to note that the 2020 International Society of Hypertension global hypertension practice guidelines 1 recommend phentolamine as a suitable option for managing blood pressure in patients with pheochromocytoma, but the more recent 2024 ESC guidelines 1 provide more specific guidance on the use of alpha-blockers like doxazosin and terazosin.
From the FDA Drug Label
Phenoxybenzamine hydrochloride capsules are indicated in the treatment of pheochromocytoma, to control episodes of hypertension and sweating. If tachycardia is excessive, it may be necessary to use a beta-blocking agent concomitantly.
- Phenoxybenzamine is a blood pressure medication that is safe for use in patients with pheochromocytoma to control episodes of hypertension and sweating 2.
- It may be necessary to use a beta-blocking agent concomitantly if tachycardia is excessive.
From the Research
Blood Pressure Medications for Pheochromocytoma
The following medications have been studied for the management of blood pressure in patients with pheochromocytoma:
- Phenoxybenzamine: an alpha-adrenergic blocking agent, effective in controlling blood pressure in most patients 3, 4, 5, 6
- Doxazosin: a specific alpha 1-adrenoceptor antagonist, shown to be as effective as phenoxybenzamine in controlling arterial pressure and heart rate, with fewer undesirable side effects 4, 6
- Propranolol: a beta-adrenergic receptor blocker, indicated for patients with tachycardia and catecholamine-induced arrhythmias, but only after adequate alpha-adrenergic blockade 3
- Alpha-methylparatyrosine (Metyrosine): a tyrosine hydroxylase inhibitor, used to decrease catecholamine synthesis, particularly in cases where surgery is contraindicated or in malignant pheochromocytoma 3, 5
Comparison of Phenoxybenzamine and Doxazosin
Studies have compared the efficacy and safety of phenoxybenzamine and doxazosin in the preoperative treatment of pheochromocytoma:
- Phenoxybenzamine may provide slightly better control of systolic arterial pressure, but is associated with more pronounced postoperative hypotension and side effects such as orthostatic hypotension, edema, and stuffy nose 4
- Doxazosin is associated with fewer side effects and may be a safer alternative for perioperative management 4, 6
Perioperative Management
The use of these medications in the perioperative period is crucial for managing blood pressure and preventing hemodynamic instability:
- Phenoxybenzamine and metyrosine may be used in combination to facilitate better blood pressure control and reduce blood loss during surgery 5
- Doxazosin has been shown to provide safe and efficacious pre- and perioperative control of arterial pressure, with fewer undesirable side effects than phenoxybenzamine 6