Spironolactone side effects and how to avoid them

In this article:

• Common side effects
• Serious side effects
• Spironolactone dosage
• How long do spironolactone side effects last?
• Contraindications
• Warnings
• Interactions
• How to avoid spironolactone side effects
• FAQ

In this article

• Common side effects
• Serious side effects
• Spironolactone dosage
• How long do spironolactone side effects last?
• Contraindications
• Warnings
• Interactions
• How to avoid spironolactone side effects
• FAQ

Spironolactone (brand names: Aldactone and CaroSpir) is a potassium-sparing diuretic (“water pill”) approved by the Food and Drug Administration (FDA) to treat congestive heart failure, high blood pressure (hypertension), edema (fluid retention) associated with liver cirrhosis or certain kidney problems, and hyperaldosteronism, which is an excess of the hormone aldosterone that can cause high blood pressure. Spironolactone is also prescribed off-label (for a non-FDA-approved use) for the treatment of hirsutism, a condition that causes excessive hair growth primarily in women, female pattern hair loss, polycystic ovarian syndrome (PCOS), and adult acne.

Spironolactone primarily works on the kidneys, increasing the elimination of water and sodium while retaining potassium. The reduction of water and sodium helps lower blood pressure in people with hypertension or hyperaldosteronism and helps reduce fluid volume in people with edema. For heart failure, spironolactone helps prevent scarring and remodeling in the heart and improves heart function. Like all diuretics, however, spironolactone may not be right for everyone. Side effects, preexisting medical conditions, and drug interactions may all require careful management. 

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Common side effects of spironolactone

Common side effects of spironolactone may include:

• Stomach problems like stomach pain, vomiting, or diarrhea
• Breast enlargement or pain (this may occur in both men and women)
• Irregular menstrual periods
• Vaginal bleeding after menopause
• Erection problems
• Voice changes (deepening)
• Increase in hair growth on the body
• Drowsiness
• Tiredness
• Restlessness
• High potassium levels 

Spironolactone may cause lightheadedness or dizziness, particularly when standing from a lying or sitting position. To minimize these effects, get up slowly when rising to a standing position.

Spironolactone side effects in females vs. males

Spironolactone side effects may affect males differently than females. That’s because it doesn’t specifically work on just one type of hormone receptor. In addition to blocking certain hormones associated with water and salt balance, it can also affect other hormones like progesterone and androgens. This can lead to side effects like irregular menstrual periods in women. In men, it may cause gynecomastia, which means swollen male breast tissue. Men may also experience problems getting or maintaining an erection. 

The effect of spironolactone on potassium levels

Elevated potassium is a common side effect of spironolactone, but the incidence is undetermined. The likelihood of elevated blood potassium will depend on age, kidney function, other medical conditions, and other drugs being taken. In the groundbreaking study of spironolactone in heart failure treatment, the incidence of severe hyperkalemia was 2% for those taking spironolactone compared with 1% for those taking a placebo (inactive medicine). The increased use of spironolactone, especially in heart failure patients, has led to an increased number of cases of hyperkalemia. The bottom line is that potassium levels will need to be monitored, particularly in people who are older, have kidney problems, have diabetes, or are taking other drugs that raise the risk of developing high potassium.

If you experience any symptoms of high blood potassium while taking spironolactone, get immediate medical attention. These symptoms include muscle weakness, fatigue, nausea, vomiting, tingling, trouble breathing, heart palpitations, irregular heartbeats, and chest pain.

Spironolactone can also cause changes in the blood’s pH, causing either acidosis (too much acid) or alkalosis (too little acid). Research suggests that acid-based imbalances may sometimes trigger unprovoked panic attacks in people already prone to panic attacks.

Serious side effects of spironolactone

Spironolactone has several potentially severe side effects:

• Severe hyperkalemia: As mentioned earlier, spironolactone can cause blood potassium levels to rise. Potassium levels that are too high (hyperkalemia) can affect the heart, leading to irregular heartbeats (arrhythmias) and, in severe cases, heart attacks. Your healthcare provider will monitor your potassium levels before and during treatment with spironolactone. 
• Electrolyte imbalances: Besides increasing potassium levels, spironolactone lowers levels of other electrolytes such as sodium, magnesium, and calcium. At severely low levels, these electrolyte imbalances can be dangerous. Your healthcare provider will monitor your electrolyte levels before and during treatment with spironolactone.
• Worsening kidney function: Decreasing water and sodium in the body can lead to dehydration, low blood volume, and ultimately compromise the ability of the kidneys to function. People taking certain types of medications, such as angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs), are more vulnerable to developing kidney problems while taking spironolactone. Your healthcare provider will monitor your kidney function before and during treatment with spironolactone.
• Liver injury (hepatotoxicity): Although rare, some patients have experienced mixed hepatitis, a condition in which liver cell injury is combined with bile backing up in the liver. Your healthcare provider will monitor your liver function before and during treatment with spironolactone.
• Blood cell problems: Patients taking spironolactone have been reported to have low white blood cell and platelet levels, which can raise the risk of infections or bleeding episodes. Your healthcare provider may monitor your blood cell counts during spironolactone treatment.
• Hypersensitivity reactions: Allergic reactions are rare. Be alert to symptoms like hives, trouble breathing, or swelling of the face, lips, tongue, or throat. Get emergency medical help right away if you have symptoms of an allergic reaction. 

Spironolactone dosage

Spironolactone is available in tablet or liquid form. The dosage your healthcare provider prescribes depends on the indication it is being used to treat.

Spironolactone dosage by indication
Indication	Standard dosage
Heart failure	25–50 mg once daily
Hypertension	Total daily doses of 25–100 mg given in a single dose or divided doses
Edema	Total daily dose of 25–200 mg given in a single dose or divided doses
Hyperaldosteronism	100–400 mg once daily in preparation for surgery (or as long-term maintenance treatment in individuals who are not having surgery)
Hirsutism (off-label)	50–200 mg once daily
Acne (off-label)	25–100 mg once or twice daily

 

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How long do spironolactone side effects last?

Many of the common side effects of spironolactone are temporary and will fade when your body gets used to the medicine. However, spironolactone’s active metabolites persist for a longer time in the body, so it may take a day or more for some temporary side effects to diminish. Other side effects, such as minor electrolyte imbalances (including hyperkalemia), may take longer to resolve. Severe electrolyte imbalances will require IV electrolyte replacement in a medical setting. Low white blood cell counts, low platelet counts, and severe allergic reactions may take several days to resolve. Drug-induced liver and kidney injury are rare but could evolve into long-term or lifelong medical conditions. 

Spironolactone contraindications 

Spironolactone is contraindicated for certain people, meaning they should never take it. This includes people with:

• High potassium levels in the blood
• Known hypersensitivity to the drug
• Addison’s disease, or adrenal insufficiency, since it may cause potentially hazardous high blood potassium and low blood pressure

Spironolactone also should not be taken in combination with the drug Inspra (eplerenone). 

Spironolactone warnings

People with certain medical conditions must be monitored while taking spironolactone and may need treatment modifications. These conditions include:

• Kidney disease
• Liver problems
• Electrolyte abnormalities
• Diabetes
• Low blood volume

Overdose

A spironolactone overdose can be fatal, but the median lethal dose is extremely high, far greater than the maximum recommended dose of 400 mg per day. If too much spironolactone is taken, the symptoms are similar to spironolactone’s side effects: sleepiness, dizziness, mental confusion, skin rash, nausea, vomiting, or diarrhea. If a spironolactone overdose is suspected, seek emergency medical help.  

Abuse and dependency

Spironolactone does not create physical dependency or cause withdrawal symptoms when discontinued. However, spironolactone is often abused, primarily by athletes seeking to rapidly lose weight or mask banned substances in the urine. For this reason, the World Anti-Doping Agency has banned athletes from using spironolactone both in and out of competition.

Children

According to the prescribing information, spironolactone is not FDA approved for use in children and adolescents. However, some healthcare professionals may prescribe this medicine off-label for certain medical conditions in patients 18 years or younger.

Pregnancy 

Many of the conditions spironolactone treats also threaten the health of the mother and the fetus. For example, spironolactone may disrupt the sex differentiation of a male fetus. Women who are pregnant or considering pregnancy should discuss the risks and benefits of taking spironolactone while pregnant.

Breastfeeding

Women who are breastfeeding or plan to breastfeed should consult with a healthcare provider before taking spironolactone. 

In the body, spironolactone is metabolized, or broken down, into different substances that are responsible for the therapeutic and adverse effects of the medication. Canrenone is one of several important active metabolites. Spironolactone itself is not present in breast milk, but canrenone is in very tiny amounts. The long-term safety of exposing an infant to even these small amounts has not been determined. 

Older adults

Spironolactone can be used to treat people older than 65, but kidney function may need to be tested and monitored.

Spironolactone interactions

Certain drugs, such as Inspra (eplerenone) or Parnate (tranylcypromine) should never be taken in combination with spironolactone. 

Certain drugs and supplements may affect the effectiveness of spironolactone or increase the risk of side effects. These spironolactone interactions include:

• Potassium: Because of the risk of high potassium levels, drugs or supplements containing potassium should be avoided.
• Drugs that increase potassium levels: Elevated serum potassium is more likely when spironolactone is combined with drugs that have the potential to increase blood potassium levels. These include ACE inhibitors, angiotensin receptor blockers (ARBs), nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen, the blood thinner heparin, and the antibiotic trimethoprim. NSAIDs may also reduce the therapeutic effectiveness of spironolactone.
• Drugs that lower blood pressure: Spironolactone lowers blood pressure and is often prescribed along with other blood pressure medications. Blood pressure monitoring may be required when drugs that lower blood pressure are combined. 
• Drugs that increase blood pressure: Drugs or substances that increase blood pressure can offset spironolactone’s therapeutic effects on blood pressure. These include caffeine, stimulants (such as amphetamines for ADHD), wakefulness agents, oral nasal decongestants, asthma medications (bronchodilators), corticosteroids, sympathomimetics, and weight loss medications. These drugs aren’t necessarily prohibited, but doses or therapies may need to be modified. 
• Nephrotoxic (kidney-damaging) drugs: Some drugs may damage the kidneys, and that risk is increased when they are combined with a diuretic such as spironolactone. Significant nephrotoxic drugs include acetaminophen, NSAIDs, salicylates, aminoglycoside antibiotics, some antiviral drugs, some diabetes medications (GLP-1 agonists), and some chemotherapy drugs. Diuretics may also interfere with the elimination of these drugs, raising their concentration in the blood and the risk of their particular side effects. Some of these drugs may need to be avoided, but most will require caution and monitoring.
• Cholestyramine: When combined with spironolactone, cholestyramine raises the risk of too much acid in the blood due to high blood potassium.

Spironolactone also increases the concentration of lithium (for bipolar disorder) and digoxin (for heart problems), raising the risk of side effects from those drugs. The combination may require regular monitoring.

How to avoid spironolactone side effects

Although side effects may occur while taking spironolactone, there are ways to lessen or entirely prevent them. 

1. Take spironolactone as directed

Take the dose as prescribed. Do not increase or decrease the dose. You can take spironolactone with or without food as long as you take it consistently. For example, don’t take it without food one day and with food the next. That’s because taking spironolactone with food substantially increases the body’s absorption of the drug and the plasma concentration of its active form. As a result, taking spironolactone with food is like taking a higher dose. That’s okay as long as it remains consistent from day to day. If effectiveness or side effects are a problem, talk to your healthcare provider about adjusting the dose.  

2. Tell your healthcare provider about all medical conditions and medications

Because of the risk of side effects, your prescribing healthcare provider needs to know about all medical conditions you have and medications you take before prescribing spironolactone, including:

• Any medical conditions, especially 
  • Addison’s disease
  • High levels of potassium in the blood
  • Diabetes
  • Urination problems
  • Electrolyte imbalances
  • Renal impairment
  • Liver disease
  • Heart disease
  • Pregnancy or breastfeeding
• All medications, including prescription and over-the-counter medications, supplements, and remedies being taken

3. Keep all follow-up visits

To minimize potential adverse effects of spironolactone, your healthcare provider may require follow-up visits and tests to monitor blood pressure, electrolytes, blood volume, kidney function, and liver function so they can spot issues before they become serious problems.

4. Follow your healthcare provider’s dietary recommendations

While taking spironolactone, your healthcare provider may tell you to limit salt intake. Salt substitutes that contain potassium should be limited as well, as they can raise your potassium levels too much. If you have low potassium, your provider may also recommend adding foods that are high in potassium, such as bananas, orange juice, and prunes. 

5. Avoid potassium supplements

Spironolactone may cause high potassium levels in the blood, a potentially dangerous condition. Many spironolactone side effects are due to high potassium, so it’s a good idea to avoid dietary supplements that contain potassium when taking spironolactone.

6. Do not substitute tablets and oral solution

Spironolactone oral solution is therapeutically different from the spironolactone oral tablets. Doses will be different. If you need to switch formulations, your healthcare provider can issue a new prescription.

Frequently asked questions about spironolactone

What are some health benefits of spironolactone?

Taking spironolactone in combination with other medications for hypertension and heart failure can reduce the risk of strokes and heart attacks. It may also lessen the need for hospitalization due to heart failure.

Is spironolactone bad for HRT?

The goal of feminizing hormone therapy is the development of female sex characteristics and the minimization of male secondary sex characteristics. Suppression and blocking of the male hormone testosterone leads to the suppression of male sexual characteristics, and spironolactone is the most commonly used androgen blocker. 

Does taking spironolactone cause weight gain or weight loss?

Weight changes are not a common side effect of spironolactone. Any weight loss is likely due to its diuretic activity since it helps eliminate excess water from the body. There is no clinical evidence showing weight gain is caused by taking spironolactone.

Can spironolactone be used to treat COVID-19?

Spironolactone has been reported to provide protection during the various stages of COVID-19 infection, particularly in high-risk patient groups such as those with obesity or preexisting hypertension. However, COVID-19 is not an FDA approved use for spironolactone. You can ask your healthcare provider for more information and medical advice. 

Does spironolactone cause voice deepening?

Spironolactone may affect the voice and cause deepening. Tell your healthcare provider if you have this side effect and if it bothers you.

How long does spironolactone take to work for acne?

Although a decrease in acne breakouts and skin oiliness may be noticeable after a few weeks of treatment, it may take three to six months for spironolactone to have its full effect.