Pharm

Eplerenone

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Eplerenone, Inspra, Selective Aldosterone Receptor Antagonist, Selective Aldosterone Blocker, Aldosterone Antagonist

  • Mechanism
  1. Eplerenone and Spironolactone are Potassium-Sparing Diuretics (as are Triamterene and Amiloride)
  2. Eplerenone and Spironolactone are also both Selective Aldosterone Receptor Antagonists
    1. Eplerenone is more selective for Aldosterone than Spironolactone
  • Pharmacokinetics
  1. Liver metabolism to active metabolite (canrenone)
  2. Half-Life: 4-6 hours
  • Dosing
  1. Hypertension
    1. Start: 50 mg orally daily
      1. Decrease starting dose to 25 mg orally daily if using strong Cytochrome P450 3A4 inhibitor
    2. May increase to 50 mg orally twice daily after 4 weeks
  2. Congestive Heart Failure
    1. Start: 25 mg orally daily for 4 weeks (then increase to target dose if tolerated)
    2. Target: 50 mg orally daily
  • Drug Interactions
  1. Increased Serum Potassium (Hyperkalemia risk)
    1. Potassium Supplementation
    2. NSAIDs
    3. ACE Inhibitor
    4. Trimethoprim-Sulfamethoxazole
  2. Digoxin
    1. Increased Digoxin Toxicity risk via increased Digoxin half life
  3. Norepinephrine
    1. Decreases NorepinephrineVasopressor activity
  4. Cytochrome P450 3A4 inhibitors (e.g. Ketoconazole, Itraconazole)
    1. Significantly increases Eplerenone levels
    2. Limit max Eplerenone dose to 25 mg daily or twice daily if used with a strong CYP 3A4 inhibitor
  • Safety
  1. Pregnancy Category B
  2. Unknown Safety in Lactation
  • References
  1. Olson (2020) Clinical Pharmacology, Medmaster, Miami, p. 62-3
  2. Hamilton (2010) Tarason Pocket Pharmacopeia, p. 74
  3. (2003) Lexi-Comp Drug Database
  4. (2003) Med Lett Drugs Ther 45(1156):39-40 [PubMed]
  5. Stier (2003) Heart Dis 5(2):102-18 [PubMed]