What is spironolactone?
Spironolacton is an aldosterone antagonist and potassium-saving diuretic. It inhibits the effect of the hormone Aldosterone, which is responsible for water and salt retention. In contrast to furosemid and torasemid, Spironolacton does not lead to potassium loss, but saves potassium.
The RALES study has shown that low dosed spironolactone reduces mortality by 30% with severe heart failure – a groundbreaking result. Spironolacton is used in heart failure, therapy-resistant high blood pressure, liver cirrhosis with ascites and primary hyperaldosteronism.
Spironolacton also has antiandrogenic properties, which is used in women for treating hormonal acne and milletrutism, but in men can lead to gynecomastia (breast enlargement).
Active Ingredients & Mechanism of Action
Active ingredient: Spironolacton
Spironolacton blocks the mineralocorticoid receptor (aldosterone receptor):
Active mechanism:
- Competitive inhibition of aldosterone on mineralocorticoid receptor
- Aldosterone can no longer trigger sodium resorption and potassium secretion
- Sodium and water are separated
- Potassium is saved (calcium-saving diuretic)
For heart failure:
- Prevents the harmful effect of aldosterone on the heart
- Reduced cardiac fibrosis (snoring)
- Improves endothelial function
- Reduces mortality by 30% (RALES study)
Antiandrogen effect:
- Blocks androgen receptors
- inhibits testosterone production
- Can improve acne and milletutism in women
- Can cause gynecomastia and potency disorders in men
Initiation of action: Slow impact over 2-3 days. Full effect only after 1-2 weeks. Long duration of action by active metabolites canrenone (half value time 16-20 hours).
Who is it suitable for?
Spironolacton is suitable for:
- Chronic heart failure (NYHA III-IV, as additional therapy)
- Treatment-resistant high blood pressure (as a 4th drug)
- Primary Hyperaldosteronism (Conn Syndrome)
- Liver cirrhosis with ascites and edema
- Hypokaliemia by other diuretics
Especially recommended at:
- Serious heart failure (life saving!)
- High blood pressure that does not appeal to 3 drugs
- Conn Syndrome (Aldosterone-producing adenoma)
- Liver cirrhosis with ascites
Not suitable:
- Heavy kidney failure (GFR below 30 ml/min)
- Heavy hyperkaliemia
- Morbus Addison
- Anurie
- At the same time with Eplerenon
Available Dosages
Sufficiency:
- 25-50 mg once a day
- For potassium under 5.0 mmol/l: 25 mg
- For potassium over 5.5 mmol/l: reduce or pause dose
Therapy-resistant high blood pressure:
- 25-50 mg once a day
Leberzirrhose mit Aszites:
- start dose: 100 mg daily
- Up to 400 mg daily possible
- In combination with furosemide (ratio 100:40)
Primary hyperaldosteroneism:
- 100-400 mg daily
Available starches:
- 25 mg, 50 mg, 100 mg tablets
How to Take
Intake:
- Once a day, preferably morning or midday
- At or after meals (improved reception)
- With sufficient water
Important notes:
- Engmaschige Potassium Controls (Calium can increase dangerously!)
- No potassium supplements without medical instructions
- No calcium-containing salt substitutes
- Control kidney values regularly
- For potassium over 5.5 mmol/l: contact doctor immediately
Monitoring:
- Potassium and creatine: after 1 week, 4 weeks, then every 3 months
- In case of heart failure: tighter controls
Contraindications
**Spironolactone must not be taken at:* *
- Heavy hyperkalemia (over 5.5 mmol/l)
- Heavy kidney failure (GFR below 30 ml/min)
- Morbus Addison
- Anurie
- At the same time with Eplerenon
- hypersensitivity to Spironolacton
Preview at:
- Moderate renal insufficiency
- Simultaneous intake of ACE inhibitors/sartans (hyperkaliemia risk!)
- Diabetes mellitus (hyperkalemia risk increased)
- Simultaneous NSAR intake
- Older patients
pregnant: Contrainded in the first trimester. The antiandrogenic effect can interfere with the development of male fetuses.
Possible Side Effects
Acid (1-10%):
- Hyperkaliemia (most important side effect!)
- Gynecomastia in men (dose dependent, up to 10%)
- Breast tensions and sensitivity
- Gastrointestinal complaints
- tiredness, sleepiness
- Headaches
** Occasionally (0,1-1%):* *
- Menstrual disorders in women
- Changes in mood in women
- Potency disorders in men
- Skin rash
- nausea, vomiting
- Muscle cramps
Selten:
- Heavy hyperkalemia (life threatening!)
- Hyponatriemia
- Metabolic aziosis
- liver value increases
- Blood-image changes
Gynecomastia: Breast enlargement in men is dose-dependent and reversible after depletion. Alternative incompatibility: Eplerenon (selective, less antiandrogen).
Interactions
**Dangerous combinations (hyperkaliemia risk!):* *
- ACE inhibitors and sartans → narrow-meshed potassium controls!
- Potassium supplements → contraindicated
- Other potassium-saving diuretics (triamteren, Amilorid) → contraindicated
- Eplerenon → contraindicated
- Trimethoprim → enhanced hyperkalemia
Preview at:
- NSAR → reduced diuresis, hyperkalemia
- Lithium → increased lithium mirror
- Digoxin → increased digoxin level (but hyperkalemia protects against digitalis toxicity)
- Antihypertensive → increased blood pressure reduction
Important: The combination of spironolactone with ACE inhibitors/sartans is standard for heart failure, but requires close-meshed potassium controls. The risk of severe hyperkalemia is real!
Frequently Asked Questions
Similar Medications
Is spironolactone right for you?
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Important Notice
This information does not replace medical advice. If you have questions about your health or the suitability of this medication, please consult a doctor or pharmacist.
Important Safety Information
This service operates under German pharmaceutical law (HWG). For risks and side effects, read the package leaflet and consult your doctor or pharmacist. All medications are dispensed from a licensed pharmacy in Germany.