Can Aldactone (spironolactone) cause hyponatremia?

Spironolactone Can Cause Hyponatremia

Yes, spironolactone (Aldactone) can cause hyponatremia as a documented adverse effect, particularly at higher doses or when used in combination with other diuretics. This is clearly stated in the FDA drug label and supported by multiple clinical guidelines.

Mechanism and Risk Factors

• Spironolactone is an aldosterone antagonist that can cause electrolyte disturbances, including hyponatremia, by affecting renal sodium handling 1
• The risk of hyponatremia is increased in certain clinical scenarios:
  • Higher doses (50-100 mg) are more likely to cause hyponatremia than lower doses (25 mg) 2
  • Concomitant use with loop diuretics like furosemide significantly increases the risk 2
  • Advanced age, diabetes mellitus, and alcohol consumption are independent risk factors when combined with spironolactone 2

Clinical Evidence

• The FDA drug label explicitly lists hyponatremia as an adverse reaction under "Electrolyte and Metabolic Abnormalities" 1
• In cases of spironolactone overdose, hyponatremia is specifically mentioned as a potential manifestation 1
• Guidelines for managing cirrhosis with ascites acknowledge that diuretic therapy, including spironolactone, can cause hyponatremia 3
• Most experts agree that diuretics should be temporarily stopped when serum sodium decreases to less than 120-125 mmol/L 3

Clinical Management

• Monitor serum electrolytes periodically, especially during the first weeks of treatment 3
• Consider dose reduction or temporary discontinuation if serum sodium drops below 125-130 mmol/L 3
• In patients with cirrhosis, diuretic-induced weight loss should not exceed 0.5 kg/day in patients without peripheral edema and 1 kg/day in those with edema to prevent hyponatremia 3
• Be particularly cautious when using spironolactone in:
  • Elderly patients 2
  • Patients with diabetes 2
  • Patients with alcohol consumption 2
  • Patients already receiving other diuretics 2

Special Considerations

• The combination of spironolactone with furosemide increases the risk of hyponatremia compared to either agent alone 2
• When treating heart failure, the risk of hyponatremia must be balanced against the benefits of spironolactone therapy 3
• In cirrhosis, hyponatremia is associated with higher prevalence of refractory ascites, hepatic encephalopathy, spontaneous bacterial peritonitis, hepatorenal syndrome, and mortality 3

Monitoring Recommendations

• Check serum sodium within 1-2 weeks after initiating therapy or changing doses 3
• More frequent monitoring is warranted in high-risk patients (elderly, those on multiple diuretics, or with renal impairment) 3, 1
• For patients with heart failure, regular electrolyte monitoring is essential, particularly when spironolactone is combined with ACE inhibitors or other potassium-sparing agents 3

While spironolactone is a valuable medication for treating conditions like heart failure and cirrhosis with ascites, clinicians must remain vigilant about the potential for hyponatremia, especially in vulnerable populations and at higher doses.