From the Guidelines
Beta blockers should not be used in the treatment of pheochromocytoma without prior alpha blockade, as this can lead to a dangerous hypertensive crisis. The use of beta blockers alone in pheochromocytoma patients can block the vasodilatory effects of epinephrine at beta-2 receptors, while leaving alpha-receptor mediated vasoconstriction unopposed, resulting in increased peripheral vascular resistance and severe hypertension 1.
Key Considerations
- The correct approach is to first establish adequate alpha blockade, typically with medications like phentolamine, for a sufficient period before introducing beta blockers 1.
- Phentolamine, a competitive alpha-receptor blocking agent, is useful in managing the adrenergic drive associated with pheochromocytoma 1.
- Urapidil and nitroprusside are additional suitable options for managing pheochromocytoma, and can be used as alternatives to phentolamine 1.
- Beta-blockers should only be used once alpha-blockers have been introduced to avoid acceleration of hypertension 1.
Management Approach
- Establish adequate alpha blockade before introducing beta blockers to control tachycardia or arrhythmias.
- Use phentolamine, urapidil, or nitroprusside as first-line treatment options for pheochromocytoma.
- Consider the sequential blockade approach when preparing patients for surgical removal of the pheochromocytoma to prevent intraoperative hypertensive crises and cardiovascular complications 1.
From the Research
Pheochromocytoma Treatment
- Pheochromocytoma is a rare tumor of the adrenal gland that can cause high blood pressure, heart palpitations, and other symptoms.
- The treatment of pheochromocytoma typically involves surgery to remove the tumor.
Preoperative Treatment
- Preoperative treatment with alpha-blockers, such as phenoxybenzamine or doxazosin, is often used to control blood pressure and prevent hemodynamic instability during surgery 2, 3, 4.
- Beta-blockers are sometimes used in conjunction with alpha-blockers to control reflex tachycardia, but their use is not recommended as a first-line treatment for pheochromocytoma 2.
Risks of Beta-Blockers
- The use of beta-blockers in pheochromocytoma patients can lead to unopposed alpha-adrenergic receptor stimulation, which can cause a worsening of hypertension and increase the risk of cardiovascular complications 5.
- Therefore, beta-blockers should not be used as a primary treatment for pheochromocytoma, and their use should be avoided unless absolutely necessary.
Alpha-Blocker Comparison
- Studies have compared the efficacy of phenoxybenzamine and doxazosin in controlling blood pressure and preventing hemodynamic instability during pheochromocytoma surgery 2, 3, 4.
- While phenoxybenzamine may be more effective in controlling blood pressure, doxazosin may have a more favorable side effect profile and is often less expensive 4.