What Is Spironolactone?

Spironolactone (Aldactone) is a medication that targets conditions such as high blood pressure, liver and kidney disorders, and fluid retention. It’s part of a class of drugs known as potassium-sparing diuretics and can help to keep conditions such as the aforementioned under control to help stop them from spiraling into something worse. 

Spironolactone is usually taken once a day and is mostly recommended to be taken at night which is because it can cause drowsiness. Unlike some medicines it isn’t a requirement to be taken with food so can be taken right before bed should you wish.

How Does Spironolactone Work?

Spironolactone is a highly effective drug that works to target a specific hormone within the body and change its effect. For example, Aldosterone is a hormone that acts on the kidneys to increase the reabsorption of sodium and the excretion of potassium which can lead to fluid retention and higher blood pressure. 

Spironolactone is an aldosterone receptor antagonist which means it works to slow this process down and stop the negative effects of this hormone. It basically binds to the aldosterone receptors which blocks the action of aldosterone and prevents sodium from being reabsorbed by the kidneys.

What Is Spironolactone Used For?

Spironolactone is used to aid with a plethora of medical conditions, mainly those that are impacted by hormone regulation and fluid balance. It is essentially used to help lower blood pressure and prevent water retention in the body. 

It can also assist with other medical conditions such as those with heart failure; Spironolactone can alleviate the symptoms associated with this and improve the heart’s ability to pump blood. It can also manage edema, Primary Hyperaldosteronism, PCOS (Polycystic Ovary Syndrome), Hormonal Acne, and more.

What Are the Side Effects of Spironolactone?

As with any medication, Spironolactone doesn’t come without its side effects. It’s down to the individual to speak to their medical provider and decide if the medication is right for them.

The main side effects include:

Common side effects:

• Increased Urination
• Dehydration
• Dizziness or Lightheadedness
• Headache
• Gastrointestinal Distress
• Electrolyte Imbalances
• Breast Tenderness or Enlargement
• Irregular Menstrual Cycles
• Fatigue
• Skin Reactions
• Changes in Libido
• Mood Changes
• Muscle Cramps
• Hypotension
• Increased Blood Urea Nitrogen (BUN) and Creatinine Levels

More severe: 

• Anaphylaxis shock
• The whites of your eyes or your skin turn yellow signaling liver issues
• A slow or irregular heartbeat, tingling feeling, muscle weakness or shortness of breath
• Severe dehydration
• Diarrhea, feeling sick or confused which can be a sign of issues with your kidney function

How to Take Spironolactone?

The way you take Spironolactone should be discussed with your healthcare provider before you take it. It is vital you follow instructions to ensure the medicine is effective and that you minimize the risk of any side effects.

A typical dose would be between 25-100 milligrams and this is usually taken once a day, with or without food. You should try and take it at the same time every day to reduce the risk of it impacting your stomach, but if you do miss a dose, it’s important you take it as soon as you remember.

Frequently Asked Questions About Spironolactone

What to Avoid While Taking Spironolactone?

When taking Spironolactone, it is important to avoid certain activities and foods as it could have an effect on how your body responds.

Here are some things to avoid:

• High-Potassium foods – Spironolactone is a potassium-sparing diuretic, meaning it helps your body get rid of sodium and water but retains potassium. Eating foods high in potassium could lead to dangerously high levels of potassium in your blood.
• Avoid low-sodium salt or salt substitutes – These usually contain a lot of potassium. Together with Spironolactone, they can lead to dangerously high levels of potassium in your blood.
• Alcohol – Alcohol can lower your blood pressure and it can also enhance some of the side effects of spironolactone such as dizziness or drowsiness.
• Heavy Exercise – In combination with Spironolactone, heavy exercise can cause dehydration and electrolyte imbalances.
• Extreme heat – Extreme heat can also lead to dehydration.
• Medication – Medication like other diuretics, NSAIDs, ACE inhibitors, certain steroids, and Lithium can either interact with Spironolactone or reduce its effectiveness. 

The list above is in no way exhaustive and it’s important to speak. with your medical provider for more advice on what you should avoid while taking Spironolactone.

What Medication Should Not Be Taken With Spironolactone?

Spironolactone should not be taken with certain other medications as it can reduce its effectiveness, enhance its side effects, or have other negative effects.

These medications include:

• NSAIDs
• Diuretics
• ACE inhibitors
• Angiotensin II Receptor Blockers
• Lithium
• Antidiabetic medications
• Steroids
• Antiarrhythmic drugs
• Potassium supplements
• Some antibiotics such as trimethoprim

There are many other possible drug interactions with spironolactone, so it’s important to speak to your doctor about any existing medication you are on before starting Spironolactone. Also, make sure to contact your doctor if you plan on starting any new medication while taking Spironolactone.

How Long Does It Take for Spironolactone to Work?

The time it takes for Spironolactone to work will depend on the condition it is used to treat and on the individual’s body. Here are some examples of how long it usually takes:

• High Blood Pressure – It should take a few weeks to see an effect.
• For acne – Depending on the individual and the dosage you might see some changes within weeks but it usually takes months (3 to 6) to see any significant improvements.

Again, it all depends on the individual and the condition it is used to treat. Speak with your healthcare provider to get a better idea of how long it might take for you.

What Is the Typical Dosage for Spironolactone?

The dosage of Spironolactone will depend on the condition it is being used to treat and the individual taking it.

In general, a typical dosage would be between 25-100 milligrams and this is usually taken once a day.

You should always follow your doctor’s instructions and discuss the best dosage for you with them.

Do You Need a Prescription for Spironolactone?

Yes, you need a prescription from a licensed medical professional for Spironolactone.

Can You Get Spironolactone Over-The-Counter (OTC)?

No, Spironolactone is not available over the counter (OTC). You need a prescription from a licensed medical professional to get it.

For more detailed information about spironolactone, you can refer to the following sources:

• Aldactone prescription label, Food and Drug Administration (FDA).
• Spironolactone, Drugs.com.
• Spironolactone, MedlinePlus.
• Spironolactone, U.S. National Library of Medicine.

The content on this page has been medically reviewed for accuracy and comprehensiveness by Amy Dougherty, FNP-BC, AGAC