Spironolactone is a generic drug prescribed for certain conditions, such as high blood pressure in adults. As with other drugs, spironolactone can cause side effects, such as dizziness and high blood potassium levels.

Spironolactone oral tablet is available as the brand-name drug Aldactone. Spironolactone also comes as an oral liquid suspension called CaroSpir, but this article does not cover it.

Read on to learn about spironolactone’s potential common, mild, and serious side effects. For a look at the drug’s uses and other details, see this in-depth article on spironolactone oral tablet.

Spironolactone can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took spironolactone in clinical trials:

Mild side effects can occur with spironolactone use. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to the spironolactone prescribing information.

Mild side effects that people taking Spironolactone have reported include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking spironolactone and want to tell the FDA about it, visit MedWatch.

Spironolactone may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to the drug’s prescribing information.

If you develop serious side effects while taking spironolactone, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects and their symptoms that people taking Spironolactone have reported include:

For more information about hyperkalemia and gynecomastia, see “Spironolactone: Side effect specifics” later in this article.

Note: Sex and gender exist on spectrums. Use of the terms “male” and “female” in this article refers to sex assigned at birth.

ALLERGIC REACTION

For some people, spironolactone tablets can cause an allergic reaction.

In general, symptoms of allergic reaction can be mild or serious.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to spironolactone, your doctor may recommend taking a different medication instead.

Spironolactone may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Does spironolactone cause some side effects only in women?

Yes, spironolactone can cause certain side effects only in females, such as changes in menstrual periods or bleeding. This can include:

These symptoms may go away as your body adjusts to the medication. If you have bothersome changes in your period while taking spironolactone, talk with your doctor. They can recommend ways to help manage your symptoms.

How do the side effects of 25 mg of spironolactone compare to the side effects of higher doses?

Many spironolactone side effects are dose-dependent. This means these side effects are more likely to occur when you take a higher dose. Side effects that are more likely with higher doses include:

  • menstrual irregularities
  • breast tenderness
  • reduced sex drive
  • breast growth in males
  • high blood potassium level

Other side effects, such as headache, dizziness, and fatigue, do not appear to occur more often at higher doses.

The recommended dosage of spironolactone for high blood pressure is 25 milligrams (mg) to 100 mg per day. So 25 mg per day is considered a low dosage. Your doctor may decide to increase your dosage. But they’ll prescribe the smallest dosage that manages your blood pressure.

Talk with your doctor if you have questions about side effects with your specific spironolactone dosage. This includes those that develop or worsen after dosage increases. Your doctor can help determine the best way to manage your side effects.

Learn more about some of spironolactone’s potential side effects. To find out how often side effects occurred in clinical trials, see the drug’s prescribing information.

Hyperkalemia

Spironolactone can cause hyperkalemia (high potassium level). Reports of small increases in potassium levels were common in the drug’s clinical trials. Mild hyperkalemia typically doesn’t cause any symptoms but very high potassium levels can cause symptoms such as:

The risk of very high levels of potassium during spironolactone treatment is higher in people who:

What you can do

Be sure you tell your doctor about all the medications you currently take. Also try to avoid foods high in potassium, including over-the-counter (OTC) potassium supplements and potassium-containing salt substitutes.

Your doctor will likely order blood tests to check your potassium level regularly while you’re taking spironolactone. They may decide to lower your dose or switch to a different medication if your potassium level becomes too high.

If you have questions about potassium in your diet or other drugs that raise your potassium level, talk with your doctor or pharmacist.

Gynecomastia

Gynecomastia (breast growth in males) is a potential side effect of spironolactone. This was one of the most common side effects reported in the drug’s clinical trials. Symptoms can include breast tenderness or swelling.

Gynecomastia is more likely to occur in people taking a higher dose of spironolactone. It can happen anytime within 1 or 2 months to more than a year or longer after starting spironolactone.

What you can do

Talk with your doctor if you experience bothersome breast side effects. They may recommend a lower dose or a different medication. Your doctor can advise you about all your treatment options. Your symptoms will typically go away once you stop treatment with spironolactone.

Below is important information you should consider before taking spironolactone.

Other precautions

Before starting spironolactone treatment, discuss your health history with your doctor. This medication may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.