Spironolactone

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Administration

Adult Dosing

Edema

Hypertension

  • 25-50mg/day PO divided qd-bid
    • Start: 12.5mg PO qd

Hyperaldosteronism, primary

  • 100-400mg PO qd

Hypokalemia, diuretic-induced

  • 25-100mg/day PO divided qd-qid

CHF, NYHA Class III/IV

  • 25mg PO qd
    • Use with standard treatment; may increase to 50mg/day after 8wk for worsening CHF if K stable
    • May decrease to 25mg qod if hyperkalemia; hold if K >5 mEq/L or creatinine >4mg/dL

Hirsutism, idiopathic

  • 50-200mg PO qd
    • Off label use

Acne vulgaris

  • 50-200mg PO qd
    • Start: 25mg PO qd
    • Off label use

Pediatric Dosing

Edema

  • 1-3.3mg/kg/day PO divided qd-qid
    • Max: 3.3mg/kg/day up to 200mg/day
    • Off label use

Hyperaldosteronism test

  • 125-375mg/m^2/day PO divided bid-qid
    • Max: 375mg/m^2/day
    • Off label use

Special Populations

Renal Dosing

  • CrCl <10, anuria, or acute renal impairment: contraindicated

Hepatic Dosing

  • Caution advised with hepatic impairment

Contraindications

  • Allergy to class/drug
  • CrCl <10
  • anuria
  • renal impairment, acute
  • hyperkalemia
  • Addison disease

Adverse Reactions

Serious

  • anaphylaxis
  • Stevens-Johnson syndrome
  • toxic epidermal necrolysis
  • drug reaction with eosinophilia and systemic sx
  • vasculitis
  • hepatotoxicity
  • renal failure
  • electrolyte imbalance
  • hyperkalemia, severe
  • arrhythmias
  • leukopenia
  • agranulocytosis
  • thrombocytopenia

Common

  • nausea/vomiting
  • abdominal cramps/pain
  • muscle cramps
  • diarrhea
  • headache
  • confusion
  • dizziness
  • somnolence

Pharmacology

  • Half-life: 1.3-2h (parent drug), 13.8-16.5h (active metabolites)
  • Metabolism: Liver
  • Excretion: Urine

Mechanism of Action

Antagonizes aldosterone receptors in the distal convoluted tubule, decreasing Na and water reabsorption and increasing K retention

Comments

See Also

References

<Epocrates, UpToDate>