Aldactone (Spironolactone)
Complete patient guide for uses, dosage, side effects, and safety information
Prescription RequiredQuick Facts
What Is Aldactone Used For?
Aldactone contains spironolactone, which works by blocking the effects of a hormone called aldosterone. This helps remove excess fluid from your body and lowers blood pressure.
Primary Uses
Aldactone treats essential high blood pressure, fluid retention (including heart failure), primary aldosteronism (hormone disorder), severe high blood pressure, low potassium levels caused by other medications, and excess body hair in women (hirsutism).
How It Works
Aldactone blocks aldosterone, a hormone that causes your kidneys to retain too much sodium and water while removing too much potassium. By working against aldosterone, it helps remove excess fluid, lowers blood pressure, and maintains proper potassium levels. For hirsutism, it also has anti-androgenic effects that reduce hair growth, thickness, and color.
Good to know: Aldactone improves the effectiveness of other blood pressure medications while helping prevent potassium loss that other diuretics can cause.
How to Take Aldactone
Take Aldactone exactly as prescribed by your doctor. The dosage varies based on your condition and response to treatment.
Dosage Instructions
Daily doses for adults range from 25 mg to 400 mg. Depending on your dose and condition, you may take it once daily or split into separate doses. For hirsutism treatment, your doctor may prescribe daily use or cycles with breaks. Children’s doses are calculated based on body weight.
What If You Miss a Dose?
Take Aldactone at the same time each day. If you miss a dose and it’s almost time for your next dose, skip the missed dose and take your next dose as scheduled. Never take a double dose to make up for a missed one.
Important: Never double your dose to make up for a missed dose, as this can cause dangerous potassium levels.
Available Tablet Strengths
Side Effects
Like all medications, this medicine can cause side effects. Most are mild and temporary, but some require medical attention.
Common Side Effects
These side effects occur relatively frequently and usually don’t require emergency care:
- Cramping or diarrhea
- Nausea or vomiting
- Drowsiness, tiredness, or feeling generally unwell
- Skin rash or itching
- Peeling skin or skin redness
- Fever or sore throat
- Unusual hair loss or thinning
- Excessive hair growth
Seek immediate medical attention if you experience:
- Frequent infections with fever, severe chills, sore throat, or mouth ulcers
- Breast enlargement (especially in men)
- Breast lumps or breast pain
- Irregular periods or no periods
- Post-menopausal bleeding
- Changes in sex drive or impotence
- Stomach bleeding, ulcers, or gastritis
- Unsteadiness when walking
- Leg cramps
- Headache
- Mental confusion or dizziness
- Shortness of breath and leg swelling from fluid buildup
Important Warnings
Aldactone has several important warnings and contraindications you should know about before starting treatment.
Who Should Not Take Aldactone
Do not take Aldactone if you’re allergic to spironolactone, pregnant or might be pregnant, breastfeeding, have severe kidney disease or aren’t passing urine, have high potassium levels, have Addison’s disease, or are taking eplerenone (another potassium-sparing diuretic).
Medical Conditions to Discuss
Tell your doctor about any medical conditions and all medications you take, including potassium supplements, salt substitutes containing potassium, other potassium-sparing diuretics, and other blood pressure medications.
Pregnancy and Breastfeeding
Aldactone should not be used during pregnancy due to possible effects on the developing baby. The drug may pass into breast milk. Women of childbearing age should use adequate contraception while taking Aldactone. Stop taking it immediately if you become pregnant.
High Potassium Risk: Aldactone can cause dangerously high potassium levels, which can affect heart rhythm. Regular blood tests are essential to monitor potassium levels.
Drug Interactions
Several medications can interact with Aldactone, potentially affecting how it works or increasing side effect risks.
Important: Always tell your doctor or dentist that you’re taking Aldactone, especially before receiving anesthesia.
- Other blood pressure medications
- Diuretics (water tablets)
- Digoxin (heart medication)
- Blood clot prevention medicines
- Potassium supplements or potassium-sparing diuretics
- Salt substitutes containing potassium
- Cholestyramine (cholesterol medication)
- Ammonium chloride (in cough/cold medicines)
- Aspirin
- NSAIDs and anti-inflammatory medicines
- Regional or general anesthetics
- Abiraterone (prostate cancer treatment)
- Lithium (depression medication)
Alcohol & Driving
Aldactone may affect your ability to drive or operate machinery safely due to potential drowsiness and dizziness.
Driving and Operating Machinery
Do not drive or operate machinery until you know how Aldactone affects you. The medication may cause drowsiness or dizziness in some people and may affect alertness.
Storage
Keep Aldactone in a cool, dry place where the temperature stays below 30°C. Store away from moisture, heat, and sunlight. Do not store in the bathroom, near a sink, in the car, or on window sills. Keep out of reach of children and do not use after the expiry date.
Overdose Information
If you think you’ve taken too much Aldactone, seek immediate medical attention. Call the Poisons Information Centre (13 11 26), contact your doctor, or go to the nearest hospital emergency department, even if you feel fine. Overdose symptoms may include nausea, vomiting, drowsiness, mental confusion, rash, diarrhea, or dehydration.
Frequently Asked Questions
The medication guide doesn’t specify food restrictions, but you should take it consistently at the same time each day as prescribed by your doctor.
Do not stop taking Aldactone suddenly. Always consult your doctor before stopping this medication, as sudden discontinuation may be harmful.
You should not consume a diet rich in potassium. While some high-potassium foods like dried fruit, bananas, and oranges are usually safe in normal amounts, avoid excessive consumption as too much potassium can cause serious heart rhythm problems.
Your doctor may do blood tests weekly at the start of treatment, monthly for the first 3 months, then quarterly for a year, and every 6 months when increasing your dose to monitor sodium and potassium levels and kidney function.
No, Aldactone should not be used during pregnancy due to possible effects on the developing baby. Women of childbearing age should use adequate contraception while taking this medication and stop immediately if they become pregnant.
Aldactone may cause irregular periods or no periods. For women being treated for hirsutism, your doctor may recommend combining it with oral contraceptives to provide regular menstrual cycles and adequate contraception.
Yes, breast enlargement may occur in men taking Aldactone. This normally goes away when the medication is stopped, though in rare cases some breast enlargement may persist. Report any breast changes to your doctor.
Important Disclaimer
This information is intended for general educational purposes only and should not be considered medical advice. Always consult your healthcare provider or pharmacist before starting, stopping, or changing any medication.
If you think you may have a medical emergency, call your doctor or emergency services immediately.