How do you differentiate treatment for hyperaldosteronism and pheochromocytoma?

Differentiation of Treatment for Hyperaldosteronism and Pheochromocytoma

The treatment approach for hyperaldosteronism and pheochromocytoma differs significantly, with pheochromocytoma requiring alpha-adrenergic blockade prior to surgery, while hyperaldosteronism is treated with mineralocorticoid receptor antagonists or surgery depending on whether it's bilateral or unilateral disease. 1, 2, 3

Diagnostic Approach

Hyperaldosteronism

• Initial screening: Aldosterone-to-renin ratio (ARR) with a cutoff value >30 and plasma aldosterone ≥10 ng/dL 4
• Confirmatory testing: Saline suppression test or oral salt-loading test 4
• Subtype determination:
  • Adrenal CT imaging
  • Adrenal vein sampling (gold standard) to determine if unilateral or bilateral 1, 4

Pheochromocytoma

• Initial screening: Fractionated plasma-free metanephrines or urinary fractionated metanephrines 1
• Confirmatory testing: Very high values require no further testing; borderline values may require stimulation or suppression tests 1
• Localization: CT or MRI imaging of abdomen and pelvis 1, 5

Treatment Algorithms

Hyperaldosteronism Treatment

1. Bilateral aldosterone production (idiopathic hyperaldosteronism):

   • First-line: Mineralocorticoid receptor antagonists 1, 4
     • Spironolactone: Start 12.5-25 mg daily, titrate up to 100 mg daily 4, 6
     • Eplerenone: Start 25 mg daily, titrate up to 50-100 mg daily (fewer sexual side effects) 4
   • Monitor potassium and renal function within 1-2 weeks of starting treatment 4
   • If blood pressure not controlled, add potassium-sparing diuretics or calcium channel blockers 6

2. Unilateral aldosterone production (adenoma):

   • First-line: Laparoscopic adrenalectomy 1, 4
   • Preoperative: Spironolactone 100-400 mg daily 3
   • For non-surgical candidates: Long-term maintenance with spironolactone 3

Pheochromocytoma Treatment

1. Preoperative management:

   • First-line: Alpha-adrenergic blockade with phenoxybenzamine 2
     • Indicated to control episodes of hypertension and sweating 2
   • If tachycardia is excessive: Add beta-blocker (only after adequate alpha-blockade) 2
   • Important: Beta-blockers should never be started before alpha-blockade to avoid hypertensive crisis 5

2. Definitive treatment:

   • Surgical removal (laparoscopic for adrenal pheochromocytomas, open approach for paragangliomas) 5
   • Careful preoperative pharmacologic preparation is essential for successful surgical outcome 5

Key Differences in Management

Aspect	Hyperaldosteronism	Pheochromocytoma
Preoperative medication	Spironolactone	Phenoxybenzamine (alpha-blocker)
Medication purpose	Control hypertension and hypokalemia	Prevent hypertensive crisis during surgery
Surgical approach	Laparoscopic adrenalectomy for unilateral disease	Laparoscopic for adrenal tumors; open for paragangliomas
Medical management	Mineralocorticoid receptor antagonists	Alpha-blockers with possible addition of beta-blockers
Monitoring	Potassium, renal function	Blood pressure, heart rate

Important Pitfalls to Avoid

1. For pheochromocytoma:

   • Never start beta-blockers before alpha-blockade (can precipitate hypertensive crisis) 5
   • Rule out pheochromocytoma before performing adrenal biopsy to prevent catecholamine crisis 1
   • Consider genetic testing for all patients with pheochromocytoma 5

2. For hyperaldosteronism:

   • Don't rely solely on CT imaging for subtype determination; adrenal vein sampling is the gold standard 1, 4
   • Monitor for hyperkalemia when using spironolactone, especially with concurrent ACE inhibitors 4
   • Watch for endocrine side effects of spironolactone (gynecomastia, sexual dysfunction) 7

3. Rare but important:

   • Consider the possibility of coexisting pheochromocytoma and hyperaldosteronism 8

By following these distinct treatment pathways, clinicians can effectively manage these different causes of secondary hypertension while minimizing complications and optimizing outcomes.