Aldactone (spironolactone) is a potassium-sparing diuretic (water pill) that prevents your body from absorbing too much salt and keeps your potassium levels from getting too low.

Aldactone is used to treat heart failure, high blood pressure (hypertension), or hypokalemia (low potassium levels in the blood).

Aldactone also treats fluid retention (edema) in people with congestive heart failure, cirrhosis of the liver, or a kidney disorder called nephrotic syndrome.

Aldactone is also used to diagnose or treat a condition in which you have too much aldosterone in your body. Aldosterone is a hormone produced by your adrenal glands to help regulate the salt and water balance in your body.

Take this medication by mouth, as directed by your doctor. If stomach upset occurs, take it with food or milk. It is best to take your dose early in the day (before 6 p.m.) to prevent having to get up during the night to urinate. Consult your doctor or pharmacist if you have any questions.

Dosage is based on your medical condition and response to therapy. In children, the dosage is also based on body weight.

Take this medication regularly in order to get the most benefit from it. Remember to use it at the same time(s) each day as directed. It is important to continue taking this medication even if you feel well. Most people with high blood pressure do not feel sick.

Take this medication exactly as prescribed. Do not increase your dose, take it more often than prescribed, or stop using this medicine without first consulting your doctor. Your condition may become worse when the drug is suddenly stopped.

Inform your doctor if your condition worsens (e.g., if you notice an increase in your routine blood pressure readings).

You should use Aldactone with caution if you have kidney problems, high levels of potassium in your blood, Addison's disease, if you are unable to urinate, or if you are also taking eplerenone.

You should not use Aldactone if you are allergic to spironolactone, or if you have:

• Addison's disease (an adrenal gland disorder);
• high levels of potassium in your blood (hyperkalemia);
• if you are unable to urinate; or
• if you are also taking eplerenone.

To make sure Aldactone is safe for you, tell your doctor if you have ever had:

• an electrolyte imbalance (such as low levels of magnesium in your blood);
• kidney disease;
• liver disease; or
• heart disease.

In animal studies, Aldactone caused certain types of tumors. It is not known whether tumors could occur in people using this medicine. Ask your doctor about your risk.

It is not known whether Aldactone will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Spironolactone can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

Drowsiness, dizziness, lightheadedness, stomach upset, diarrhea, nausea, vomiting, or headache may occur. To minimize lightheadedness, get up slowly when rising from a seated or lying position. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: increased thirst, signs of kidney problems (such as change in the amount of urine), mental/mood changes, unusual fatigue/weakness, muscle spasms, menstrual period changes, breast pain, breast enlargement (gynecomastia) in men, sexual function problems, signs of infection (e.g., fever, persistent sore throat), severe stomach/abdominal pain, persistent nausea/vomiting, vomit that looks like coffee grounds, dark urine, yellowing of the eyes/skin, easy bruising/bleeding.

This medication may lead to high levels of potassium, especially in patients with kidney problems. If not treated, very high potassium levels can be fatal. Tell your doctor right away if you notice any of the following serious side effects: slow/irregular heartbeat, muscle weakness.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

• high blood level of potassium
• kidney disease or trouble making urine
• liver disease
• an unusual or allergic reaction to spironolactone, other medicines, foods, dyes, or preservatives
• pregnant or trying to get pregnant
• breast-feeding

How should I use this medicine?

Take this medicine by mouth with a drink of water. Follow the directions on your prescription label. You can take it with or without food. If it upsets your stomach, take it with food. Do not take your medicine more often than directed. Remember that you will need to pass more urine after taking this medicine. Do not take your doses at a time of day that will cause you problems. Do not take at bedtime.

Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for selected conditions, precautions do apply.