Spironolactone
2,260 views
Cardio Drugs - Diuretics
Summary
Spironolactone is a diuretic that is used to remove excess fluid. By reducing blood volume, it can be effective in treating edema and hypertension. Importantly, spironolactone is a potassium-sparing diuretic, meaning that it increases potassium levels in the body and may even cause hyperkalemia at high doses, so you’ll want to keep a close eye on electrolyte levels. Since spironolactone causes fluid loss by way of urination, you’ll want to monitor the patient’s urine output, kidney function, and daily weights.
Key Points
- Mechanism
- Removes excess fluid (diuresis)
- Aldosterone receptor antagonist
- Blocks aldosterone and inhibits the sodium-potassium pump
- Promotes sodium and water excretion and potassium retention at the distal tubule and collecting duct
- Potassium-sparing diuretic
- Relatively weak compared to other diuretics
- Aldosterone receptor antagonist
- Clinical Use
- Hypertension
- Decreased fluid volume = lower BP
- Potassium-sparing diuretics are very weak diuretics, and are usually combined with other diuretics for the purposes of reducing potassium loss
- Edema
- Heart Failure
- Spironolactone is the diuretic of choice for heart failure, as it has been proven to greatly reduce mortality
- Ascites
- Secondary to cirrhosis
- Heart Failure
- Will lead to increased urination
- Contraindicated in patients with renal failure
- Watch for signs and symptoms of dehydration
- Closely monitor intake and output as well as BUN and creatinine
- Take in the morning to prevent nocturia
- Record daily weights - sudden weight gain is usually due to fluid retention
- Hypokalemia
- Spironolactone is a very weak diuretic and is usually combined with other diuretics (e.g. thiazide, loop) to reduce potassium loss
- High aldosterone levels
- Hypertension
- Side Effects and Adverse Reactions
- Hyperkalemia
- ACE inhibitors and ARBs also retain potassium and this combination can result in life-threatening hyperkalemia
- Monitoring potassium levels is essential
- Potassium supplements should be discontinued and potassium-rich foods should be avoided
- GI distress
- Take with food to decrease GI side effects
- Endocrine effects
- Gynecomastia, menstrual irregularities, erectile dysfunction, hirsutis
- Not a perfect aldosterone-receptor blocker; off-target blockade of testosterone and androgen receptors inhibits the action of testosterone
- Photosensitivity
- Hyperkalemia
- Removes excess fluid (diuresis)