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Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Limited Use [what does this mean?]
Generic drug name: spironolactone (speer on oh LAK tone)
GENERIC: available FAMILY: Potassium-sparing Diuretics
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Pregnancy Warning

Spironolactone caused fetal harm in animal studies. Because of the potential for serious adverse effects to the fetus, this drug should not be used by pregnant women.

Breast-feeding Warning

Spironolactone is excreted in human milk. Because of the potential for serious adverse effects in nursing infants including spironolactone’s ability to produce tumors, you should not take this drug while nursing.

Safety Warnings For This Drug [top]


Spironolactone has been shown to be a tumorigen in chronic toxicity studies in rats. Aldactone should be used only in those conditions described under Indications and Usage. Unnecessary use of this drug should be avoided.

Heat Stress Alert

This drug can affect your body’s ability to adjust to heat, putting you at risk of “heat stress.” If you live alone, ask a friend to check on you several times during the day. Early signs of heat stress are dizziness, lightheadedness, faintness, and slightly high temperature. Call your doctor if you have any of these signs. Drink more fluids (water, fruit and vegetable juices) than usual—even if you’re not thirsty—unless your doctor has told you otherwise. Do not drink alcohol.

Facts About This Drug [top]

Spironolactone (ALDACTONE) is a diuretic (water pill) that removes less of the mineral potassium from the body than other types of diuretics do. It is approved for treatment of several conditions, including high blood pressure and heart failure. Treatment with spironolactone has been shown to greatly reduce the rate of complications and death in patients with severe heart failure.[1] Doctors sometimes prescribe it for high blood pressure instead of another diuretic in the hope that it will...

Spironolactone (ALDACTONE) is a diuretic (water pill) that removes less of the mineral potassium from the body than other types of diuretics do. It is approved for treatment of several conditions, including high blood pressure and heart failure. Treatment with spironolactone has been shown to greatly reduce the rate of complications and death in patients with severe heart failure.[1] Doctors sometimes prescribe it for high blood pressure instead of another diuretic in the hope that it will prevent potassium depletion, but there is no guarantee that this will work.

Adverse effects

Spironolactone can cause severe adverse effects. It is especially dangerous for people with kidney disease.[2],[3] It can cause kidney failure, hyperkalemia (high blood potassium levels),[2],[4],[5],[6] muscle paralysis[7] and mental confusion[2] in older adults. These effects may be fatal.

Close laboratory monitoring of blood potassium levels is necessary in patients using spironolactone.[8] Because of its dangers, spironolactone is not the best drug for treating high blood pressure or water retention. Older adults should not use spironolactone just for its ability to keep potassium in the body. Patients who need extra potassium can adjust their diet or take potassium supplements. Both methods are equally effective[9] (see our article on "Potassium Supplementation") and are safer than using spironolactone. The only reason an older adult should use this drug is to control a rare condition in which the body releases too much aldosterone (a hormone that regulates potassium and sodium levels). 


Combining spironolactone with an angiotensin-converting enzyme inhibitor (ACE) inhibitor or an angiotensin II receptor blocker (ARB) increases the risk of hyperkalemia. Strict prescribing protocols must be followed in patients taking spironolactone with an ACE inhibitor or ARB, which also are used to treat hypertension and heart failure, or with the antibiotic trimethoprim-sulfamethoxazole (BACTRIM, COTRIM, SEPTRA, SEPTRA DS), another drug that increases the risk of severe hyperkalemia.[10]

(Read more in the December 2011 Worst Pills, Best Pills News.)

Bleeding and ulcers

Spironolactone also appears to be associated with an increased risk of upper gastrointestinal adverse events (bleeding and ulcers). This risk may be more pronounced when spironolactone is combined with ulcer-inducing drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen [MOTRIN]), platelet inhibitors (for example, clopidogrel [PLAVIX]), corticosteroids (for example, prednisone [DELTASONE]) or anticoagulants (for example, warfarin [COUMADIN]).[11]

First-line treatment for high blood pressure

If you have high blood pressure, the best way to reduce or eliminate your need for medication is by improving your diet, losing weight, exercising, and decreasing your salt and alcohol intake. Mild hypertension can be controlled by proper nutrition and exercise. If these measures do not lower your blood pressure enough and you need medication, the diuretic hydrochlorothiazide (ESIDRIX, HYDRODIURIL, MICROZIDE) is the drug of choice, starting with a low dose of 12.5 milligrams daily. It also costs less than other blood pressure drugs.

There is growing evidence that thiazide diuretics, such as hydrochlorothiazide, significantly decrease the rate of bone mineral loss in both men and women because they reduce the amount of calcium lost in the urine.[12] Research now suggests that thiazide diuretics may protect against hip fracture.[13]

If your high blood pressure is more severe, and hydrochlorothiazide alone does not control it, another family of high blood pressure-lowering drugs may be added to your treatment. In this case, your doctor would prescribe the hydrochlorothiazide and the second drug separately, with the dose of each drug adjusted to meet your needs, rather than using a product that joins the drugs in a fixed combination.

Whatever drugs you take for high blood pressure, once your blood pressure has been normal for a year or more, a cautious decrease in dose and renewed attention to nondrug treatment may be worth trying, according to The Medical Letter on Drugs and Therapeutics.[14]

An editorial in BMJ stated the following:

Treatment of hypertension is part of preventive medicine and like all preventive strategies, its progress should be regularly reviewed by whoever initiates it. Many problems could be avoided by not starting antihypertensive treatment until after prolonged observation... Patients should no longer be told that treatment is necessarily for life: the possibility of reducing or stopping treatment should be mentioned at the outset.[15]

Patients taking several types of commonly used antihypertensive medications, particularly diuretics, beta-blockers, ACE inhibitors and ARBs (except losartan [COZAAR]), are at increased risk of developing gout, a type of arthritis.

There is also evidence that combining NSAIDs with a diuretic plus either an ACE inhibitor or an ARB increases the risk of kidney injury.

Before You Use This Drug [top]

Tell your doctor if you have or have had:

  • allergies to drugs
  • diabetes
  • heart, kidney, or liver problems
  • menstrual problems
  • breast enlargement
  • pregnancy or are breast-feeding
  • high potassium levels
  • gout
  • kidney stones

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.

When You Use This Drug [top]

  • Do not use potassium supplements, salt substitutes (potassium chloride), or potassium-rich foods.
  • If you plan to have any surgery, including dental, tell your doctor that you take this drug.
  • Do not take any other drugs without first talking to your doctor—especially nonprescription drugs for appetite control, asthma, colds, coughs, hay fever, or sinus problems.

How to Use This Drug [top]

  • If you miss a dose, take it as soon as you remember, but skip it if it is almost time for the next dose. Do not take double doses.
  • Do not share your medication with others.
  • Take it at the same time each day. If a single dose, take it in the morning after breakfast; if more than one dose, take the last no later than 6 p.m. unless your doctor states otherwise.
  • Take with food or milk to avoid stomach irritation.
  • Store at room temperature with lid on tightly. Do not store in the bathroom. Do not expose to heat, moisture, or strong light. Keep out of reach of children.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

ATACAND, AVAPRO, benazepril, BENICAR, candesartan, CAPOTEN, captopril, cholestyramine, COZAAR, cyclosporine, digoxin, DIOVAN, enalapril, eprosartan, ESKALITH, fosinopril, irbesartan, ISMELIN, KATO, K-LOR, KLOTRIX, LANOXICAPS, LANOXIN, lisinopril, LITHANE, lithium, LOCHOLEST, losartan, LOTENSIN, MAVIK, MICARDIS, moexipril, MONOPRIL, olmesartan, potassium chloride, PRINIVIL, QUESTRAN, SANDIMMUNE, SLOW-K, telmisartan, TEVETEN, trandolapril, UNIVASC, valsartan, VASOTEC, ZESTRIL

Adverse Effects [top]

Call your doctor immediately if you experience:

  • signs of potassium imbalance: confusion; anxiety; irregular heartbeat; numbness or tingling in hands, feet, lips; difficulty breathing; unusual tiredness or weakness; heavy legs
  • sore throat and fever
  • skin rash or itching
  • cough or hoarseness
  • fever
  • chills
  • lower back or side pain
  • painful or difficult urination
  • severe or continuing nausea or vomiting
  • diarrhea
  • postmenopausal bleeding
  • breast enlargement or tenderness

Call your doctor if these symptoms continue:

  • drowsiness
  • stomach cramps
  • diarrhea
  • inability to get or keep an erection
  • unusual sweating
  • voice deepening and breast tenderness
  • increased hair growth in women
  • enlarged breasts in men<
  • irregular menstrual periods
  • dry mouth, increased thirst
  • nausea, vomiting
  • mental confusion
  • stumbling, clumsiness
  • dizziness
  • headache
  • decreased sexual ability

Periodic Tests[top]

Ask your doctor which of these tests should be done periodically while you are taking this drug:

  • blood pressure
  • complete blood count
  • kidney function tests
  • blood levels of potassium and sodium (weekly when first starting to use the drug)
  • electrocardiograms

last reviewed March 31, 2024