Generic name: Spironolactone

Aldactone is a thiazide and potassium-sparing diuretic and a high blood pressure medication. It lowers blood pressure by helping the body produce and eliminate more urine. 

Quick Facts About Aldactone


Used to treat high blood pressure. Also used to diagnose and treat hyperaldosteronism — excessive aldosterone secretion in the adrenal gland. Aldactone may also be used for: congestive heart failure, cirrhosis of the liver, kidney disease, and unusually low potassium levels.

Aldactone Dosage

Take exactly as prescribed. Sudden discontinuance of this medication may worsen your condition. Must be taken on a regular basis to be effective.

  • Usual adult dose: for high blood pressure — 50 to 100 milligrams per day in a single dose or divided into smaller doses. For congestive heart failure, cirrhosis, or kidney disorder — 100 milligrams daily in a single dose or divided into smaller doses. Doctor may prescribe as low as 25 milligrams per day or as high as 200 milligrams daily. For potassium loss — 25 to 100 milligrams per day. To detea hyperaldosteronism — 400 milligrams per day for 3 to 4 weeks, known as the long test. Short test to detect hyperaldosteronism — 400 milligrams per day for 4 days.
  • Usual child dose: 1.5 milligrams per pound of body weight daily in a single dose or divided into smaller doses.
  • Missed dose: take as soon as possible, unless almost time for next dose. In that case, do not take missed dose; go back to regular schedule. Do not double doses.

Aldactone Side Effects

Overdose symptoms:

No specific information is available regarding Aldactone overdose. If you suspect an overdose, immediately seek medical attention.

More common side effects: abdominal cramps, breast development in males, change in potassium levels, deepening of voice, diarrhea, drowsiness, excessive hairiness, fever, headache, hives, irregular menstruation, lack of coordination, lethargy, mental confusion, postmenopausal bleeding, sexual dysfunction, skin eruptions, stomach bleeding, stomach inflammation, ulcers, vomiting.

Less common Aldactone side effects: No known less common or rare side effects.


Use extreme caution if taking Vasotec or other ace-inhibitor medications.

Inform your doctor before combining Aldactone with:

Digoxin (Lanoxin), Indomethacin (Indocin), Norepinephrine (Levophed), other diuretics such as Lasix and HydroDIURIL, other high blood pressure medications such as Aldomet and Procardia XL.

No known food/other substance interactions. 

Special Cautions

If pregnant or planning to become pregnant, inform f your doctor immediately. Appears in breast milk; could affect a nursing infant

No special precautions apply to seniors.

Follow doctor’s instructions carefully for children.

  • Should not be used if you have: difficulty urinating, high potassium levels in the blood, inability to urinate, or kidney disease.
  • Avoid use of potassium supplements or other diuretics, such as Maxzide.
  • Be careful not to lose too much water from the body; blood pressure lowers dramatically.
  • Before medical or dental surgery, tell your doctor or dentist you are taking this drug.
  • Use with caution if you have liver disease.
  • Kidney function should be monitored with Aldactone use.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Aldactone side effects, please contact your healthcare provider.