spironolactone

Aldactone (spironolactone) is a potassium-sparing diuretic that removes excess fluid from the body in congestive heart failure, cirrhosis of the liver, and kidney disease. It also can be used in combination with other drugs to treat diuretic-induced low potassium (hypokalemia) and high blood pressure. Aldactone also is used to counteract the effects of excessive adrenal aldosterone production (hyperaldosteronism) that can occur from a tumor in the adrenal gland or enlarged adrenal glands (hyperplasia of the adrenal glands).

Aldactone 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. Aldactone causes increased amounts of sodium and water to be excreted, while potassium is retained. Aldactone acts both as a diuretic and as an antihypertensive drug by this mechanism. It may be given alone or with other diuretic agents that act more proximally in the renal tubule.

• Aldactone removes excess fluid from the body in congestive heart failure, cirrhosis of the liver, and kidney disease.
• It also can be used in combination with other drugs to treat elevated blood pressure, and for treating diuretic-induced low potassium (hypokalemia).
• Aldactone also is used to counteract the effects of excessive adrenal aldosterone production (hyperaldosteronism). Aldosterone overproduction can occur from a tumor in the adrenal gland or enlarged adrenal glands (hyperplasia of the adrenal glands).

Common side effects of Aldactone include:

• Headache
• Diarrhea
• Cramps
• Drowsiness
• Rash
• Nausea
• Vomiting
• Impotence
• Irregular menstrual periods
• Irregular hair growth

Enlargement of the male breasts (gynecomastia) may also occur and is related to dose and duration of therapy. It usually reverses upon discontinuation of Aldactone.

Possible serious side effects of Aldactone include:

• Liver dysfunction
• Kidney failure
• Anaphylaxis
• Abnormal heart rhythm
• Low platelets
• Low white blood cells
• Toxic epidermal necrolysis
• Vasculitis
• Risk of tumors in animal studies

Fluid and electrolytes imbalance (for example, low sodium, low magnesium, and high potassium) may occur, so patients should be monitored carefully.

• Aldactone may be taken with or without food. The dosage range is 25-400 mg daily in single or divided doses.
• The initial dose for treating edema in adults is 100 mg daily as a single dose or divided doses. The dose may be adjusted after 5 days based on response. The recommended dose range is 25 to 200 mg daily. The initial dose should be continued for at least 5 days before increasing the dose. If there is no adequate response after 5 days, a second diuretic may be added.
• The dose for treating high blood pressure (hypertension) is 50 to 100 mg daily in single or divided doses.
• The dose for treating hypokalemia is 25 to 100 mg daily.

• Aldactone can lower blood sodium levels while raising blood potassium levels. Excessively high blood potassium levels can lead to potentially life-threatening abnormalities in the rhythm of the heart. Therefore, Aldactone usually is not administered with other agents that can raise blood potassium levels, such as potassium supplements, angiotensin converting enzyme (ACE) inhibitors [for example, enalapril (Vasotec)], indomethacin (Indocin), or other potassium-sparing diuretics.
• Aldactone can cause elevation of blood digoxin (Lanoxin) to toxic levels, requiring adjustment of the digoxin dosage.

• There are no adequate studies in pregnant women. Aldactone may be harmful if used for treating gestational hypertension (high blood pressure during pregnancy).
• An active metabolite of Aldactone is secreted in breast milk. To avoid adverse effects in the newborn, mothers should avoid breastfeeding while taking Aldactone.

What preparations of spironolactone are available?

• Tablets: 25, 50, and 100 mg

How should I keep spironolactone stored?

• Aldactone should be stored at room temperature, below 25 C (77 F).