What is the primary treatment for hyperaldosteronism?

Treatment of Primary Hyperaldosteronism

The primary treatment for hyperaldosteronism depends on whether the condition is unilateral or bilateral, with surgical removal of the affected adrenal gland for unilateral disease and mineralocorticoid receptor antagonists (MRAs) for bilateral disease. 1

Diagnostic Approach to Guide Treatment

Before initiating treatment, it's crucial to determine the subtype of primary aldosteronism:

1. Initial screening: Measure plasma aldosterone and renin activity ratio (ARR)

   • Cutoff value typically ≥30 when plasma aldosterone is reported in ng/dL and plasma renin activity in ng/mL/h
   • Plasma aldosterone should be at least 10 ng/dL for a positive test 1
   • Patients should have:
     • Unrestricted salt intake
     • Normal serum potassium
     • MRAs withdrawn for at least 4 weeks before testing

2. Confirmatory testing: Intravenous saline suppression test or oral salt-loading test 1

3. Subtype determination: Adrenal venous sampling to differentiate unilateral from bilateral disease 1

   • In patients <40 years with clear unilateral adrenal lesion on imaging, adrenal vein sampling may be bypassed 1

Treatment Algorithm

For Unilateral Primary Aldosteronism (Adenoma or Unilateral Hyperplasia)

• First-line treatment: Laparoscopic adrenalectomy of the affected gland 1
  • Improves blood pressure in virtually 100% of patients
  • Completely cures hypertension in about 50% of patients
  • Exceptions: Elderly patients or those with significant comorbidities

For Bilateral Primary Aldosteronism (Idiopathic Hyperaldosteronism)

• First-line treatment: Mineralocorticoid receptor antagonists 1, 2

  1. Spironolactone:

     • Starting dose: 25-100 mg daily (single or divided doses) 2
     • Typical effective dose: 50-100 mg once daily
     • Can be titrated up to 300-400 mg daily if necessary 1
     • Side effects: Gynecomastia, decreased libido, impotence in men; menstrual irregularities in women 3

  2. Eplerenone (alternative):

     • Less potent than spironolactone
     • Requires twice-daily administration
     • Advantage: Fewer sexual side effects (less gynecomastia and erectile dysfunction) 1
     • Typical dose: 50-100 mg/day 4

• If blood pressure not normalized with MRAs:

  • Add potassium-sparing diuretics (amiloride or triamterene)
  • Add calcium channel antagonists 4

For Familial Hyperaldosteronism Type 1 (Glucocorticoid-Remediable Aldosteronism)

• Treatment: Low-dose dexamethasone 1
  • Typically free of glucocorticoid side effects
  • Safe during pregnancy

Monitoring and Follow-up

• Close monitoring of serum electrolytes and creatinine when starting medication 4
• Regular blood pressure monitoring
• Assess for resolution of hypokalemia
• For patients on MRAs, monitor for hyperkalemia, especially in those with reduced renal function 1

Important Considerations

• Early diagnosis and treatment lead to higher cure rates 1
• Treating primary aldosteronism (either surgically or medically) resolves hypokalemia, lowers blood pressure, reduces required antihypertensive medications, and improves cardiac and kidney function 1
• For malignant hyperaldosteronism (rare), open adrenalectomy is recommended as these tumors are prone to rupture 1
• In patients with reduced renal function (eGFR 30-50 mL/min/1.73m²), consider starting spironolactone at 25 mg every other day due to hyperkalemia risk 2

Pitfalls to Avoid

• Failing to distinguish between unilateral and bilateral disease before deciding on treatment
• Not withdrawing MRAs for at least 4 weeks before diagnostic testing
• Overlooking the possibility of familial forms of hyperaldosteronism
• Not monitoring electrolytes closely when initiating MRA therapy
• Relying solely on imaging without adrenal vein sampling for subtype determination in most patients

Primary aldosteronism is the most common form of secondary hypertension, and proper treatment significantly reduces cardiovascular morbidity and mortality associated with this condition.