ADVERSE EFFECTS

The major adverse effects of potassium-sparing diuretics include:

• Hyperkalemia
  
• Metabolic acidosis. Through the same mechanisms used to reduce K⁺ secretion, these agents also reduce H⁺ secretion into the distal nephron.
  
• Acute kidney injury (triamterene, owing to crystalluria and tubular obstruction)
  
• Nausea, vomiting, and diarrhea
  
• Peptic ulcers (spironolactone)
  
• Headache and lethargy
  
• Rash
  
• Antiandrogenic effects: gynecomastia and/or breast pain, impotence, hirsutism, and irregular menses (aldosterone antagonists, spironolactone more than eplerenone)