From the Guidelines
Spironolactone is a potassium-sparing diuretic medication that works by blocking the hormone aldosterone, and its use should be prioritized in patients with heart failure, high blood pressure, edema, primary hyperaldosteronism, and as an off-label treatment for acne and hirsutism in women, with careful monitoring of potassium levels and kidney function, especially when starting therapy, as indicated by the most recent study 1.
Key Points
- Spironolactone is primarily used to treat conditions like heart failure, high blood pressure, edema, primary hyperaldosteronism, and as an off-label treatment for acne and hirsutism in women.
- The typical dosage ranges from 25-100 mg daily, often starting at a lower dose and titrating up as needed.
- For heart failure, doses typically range from 25-50 mg daily, while for acne treatment in women, 50-100 mg daily is common.
- Spironolactone should be taken with food to enhance absorption.
- As it blocks aldosterone, it causes the kidneys to retain potassium while excreting sodium and water, which explains its diuretic effect.
- Common side effects include increased potassium levels, menstrual irregularities, breast tenderness, and decreased libido.
- Regular monitoring of potassium levels and kidney function is essential, especially when starting therapy, as indicated by 1 and 1.
Important Considerations
- Spironolactone should be used cautiously in patients with kidney disease and is contraindicated in those with high potassium levels or severe kidney impairment.
- It also has anti-androgenic properties, which explains its effectiveness for conditions like female acne and hirsutism by reducing the effects of male hormones on the skin and hair follicles.
- Patients taking spironolactone are at risk for developing hyperkalemia, which can cause cardiac arrest, and therefore, the patient’s potassium levels should be monitored during treatment, particularly in at-risk patients with diabetes mellitus, kidney and/or liver disorders, and elderly patients, as indicated by 1 and 1.
- Contraindications for taking spironolactone include the use of other potassium-sparing diuretics, potassium supplements, CYP3A4 inhibitors, and the combined use of an angiotensin receptor blocker and angiotensin-converting enzyme inhibitor, as indicated by 1 and 1.
From the FDA Drug Label
12 CLINICAL PHARMACOLOGY
- 1 Mechanism of Action Spironolactone and its active metabolites are specific pharmacologic antagonists of aldosterone, acting primarily through competitive binding of receptors at the aldosterone-dependent sodium-potassium exchange site in the distal convoluted renal tubule. Spironolactone causes increased amounts of sodium and water to be excreted, while potassium is retained Spironolactone acts both as a diuretic and as an antihypertensive drug by this mechanism.
The basics of spironolactone are that it is a diuretic and antihypertensive drug that works by:
- Competing with aldosterone for receptor sites
- Increasing the excretion of sodium and water
- Retaining potassium It is used to treat conditions such as edema and ascites in patients with congestive heart failure, hepatic cirrhosis, and nephrotic syndrome 2. Key points about spironolactone include:
- It is a pharmacologic antagonist of aldosterone
- It has a mean half-life of 1.4 hours
- Its metabolites are excreted primarily in the urine and secondarily in bile
- It should be taken with a routine pattern with regard to meals to increase its bioavailability.
From the Research
Basics of Spironolactone
- Spironolactone is a potassium-sparing diuretic with anti-aldosterone effects, used in the management of hypertension and heart failure 3.
- It has been shown to reduce morbidity and mortality in patients with heart failure with reduced ejection fraction and decrease hospitalizations in heart failure with preserved ejection fraction 4.
- The drug is also used in the treatment of resistant hypertension, with an average blood pressure lowering of 22/10 mm Hg in patients with resistant hypertension 3.
Indications and Contraindications
- Spironolactone is indicated for patients with heart failure, resistant hypertension, and edema in patients with cirrhosis 5, 3.
- However, it should be used with caution in patients with renal insufficiency, as it can increase the risk of hyperkalemia and acute kidney injury 4, 6, 7.
- Patients with an estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m2 and potassium > 5.0 mEq/L should not be initiated on spironolactone therapy 4.
Adverse Effects
- Common adverse effects of spironolactone include hyperkalemia, gynecomastia, and renal insufficiency 4, 6, 7, 3.
- The risk of hyperkalemia and acute kidney injury is higher in patients with renal insufficiency, and these patients should be monitored closely 4, 7.