Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes Spironolactone. If you are concerned about side effects, discuss the risks and benefits of Spironolactone with your doctor.

The following side effects have been reported by at least 1% of people taking Spironolactone. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• Diarrhea
• dizziness or lightheadedness, especially when rising from a lying or sitting position
• drowsiness
• Dry Mouth
• fatigue
• Fever
• frequent urination
• headache
• nausea
• thirst
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• confusion
• enlarged or painful breasts
• fast, slow, or irregular heartbeat
• fever
• increased infections
• irregular menstrual period
• muscle weakness or cramps
• rapid weight loss
• signs of Anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of bleeding (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs and symptoms of imbalance of water, sodium or potassium in the body (e.g., muscle pain or cramps, weakness, irregular heart beat)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine, swelling, fatigue, abdominal pain)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• signs of pancreatitis (e.g., abdominal pain on the upper left side, back pain, nausea, fever, chills, rapid heartbeat, swollen abdomen)
• skin rash
• symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• chest pain
• signs of a Anaphylaxis (severe allergic reaction) such as difficulty breathing; Hives; or swelling of the face, tongue, or throat
• signs of a severe skin reaction (e.g., blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort)
• signs of stomach bleeding such as vomiting of blood, stomach pain, black and tarry stools

25 mg
Each cream-coloured, round, biconvex, compressed tablet, and with a peppermint aroma, engraved "N" on one side and "2|5" on the reverse, contains spironolactone 25 mg. Nonmedicinal ingredients: D&C Yellow No. 10 Lake, FD&C Yellow No. 6 Lake, lactose, magnesium stearate, natural peppermint flavour, sodium lauryl sulfate, and sodium starch glycolate. Gluten- and tartrazine-free.

100 mg
Each cream-coloured, round, biconvex tablet, and with a peppermint aroma, engraved "N|N" on one side and "100" on the reverse, contains spironolactone 100 mg. Nonmedicinal ingredients: D&C Yellow No. 10 Lake, FD&C Yellow No. 6 Lake, lactose, magnesium stearate, natural peppermint flavour, sodium lauryl sulfate, and sodium starch glycolate. Tartrazine-free.

Do not take Spironolactone if you:

• are allergic to spironolactone or any ingredients of the medication
• are unable to produce urine
• have Addison's Disease
• have high blood levels of potassium
• have rapidly worsening kidney function
• have significantly reduced kidney function
• are using Eplerenone, Heparin, or a low molecular weight heparin
• are pregnant
• are breast-feeding

There may be an interaction between spironolactone and any of the following:

• Abiraterone
• Aldesleukin
• alcohol
• alpha/ beta agonists (e.g., Epinephrine, norepinephrine)
• alpha agonists (e.g., Clonidine, methyldopa)
• alpha blockers (e.g., Alfuzosin, Doxazosin, Tamsulosin)
• amifostine
• amphetamines (e.g., Dextroamphetamine, lisdexamphetamine)
• angiotensin II antagonists (e.g., Candesartan, Valsartan)
• angiotensin-converting enzyme inhibitors (ACE inhibitors; e.g., Captopril, Enalapril, Lisinopril, Ramipril)
• Atorvastatin
• barbiturates (e.g., Phenobarbital, butalbital)
• beta-adrenergic blockers (e.g., Atenolol, Propranolol, Sotalol)
• brimonidine
• calcium channel blockers (e.g., Amlodipine, Diltiazem, Nifedipine, Verapamil)
• Canagliflozin
• Cholestyramine
• ciprofloxacin
• corticosteroids (e.g., Prednisone, Dexamethasone)
• Cyclosporine
• Dapagliflozin
• diazoxide
• Digoxin
• other diuretics (water pills; e.g., Amiloride, Furosemide, Hydrochlorothiazide)
• dropspirenone
• Duloxetine
• eplerenone
• Guanfacine
• heparin
• levodopa
• lithium
• low molecular weight heparins (e.g., Dalteparin, Enoxaparin, Tinzaparin)
• Methylphenidate
• Minoxidil
• Mitotane
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, Phenelzine, Rasagiline, Selegiline, Tranylcypromine)
• narcotic medications (e.g., Codeine, Morphine)
• nitrates (e.g., Nitroglycerin, isosorbide dinitrate, isosorbide mononitrate)
• Nitrofurantoin
• nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., Diclofenac, Ibuprofen, Ketorolac, Naproxen)
• Obinutuzumab
• Pentoxifylline
• phosphodiesterase 5 inhibitors (e.g., Sildenafil, Tadalafil, Vardenafil)
• potassium-containing medications, supplements, or salt-substitutes (e.g., potassium chloride, potassium citrate, potassium gluconate, potassium iodide, potassium phosphate)
• Quetiapine
• quinidine
• salicylates (e.g., Asa, salsalate)
• Risperidone
• Rituximab
• sodium phosphates
• Tacrolimus
• Tolvaptan
• Trimethoprim
• Yohimbine

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Spironolactone. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Spironolactone.

Breast enlargement in men: Men may develop breast enlargement with the use of spironolactone. If this occurs, tell your doctor. In the great majority of cases, breast enlargement disappears once the medication is stopped.

Drowsiness and dizziness: Spironolactone may cause drowsiness or dizziness, affecting your ability to drive or operate machinery.

Avoid these and other hazardous tasks until you have determined how Spironolactone affects you. Spironolactone may also cause dizziness or lightheadedness when moving from a lying or sitting to an upright position.

Alcohol can add to the drowsiness caused by this medication.

Potassium: Spironolactone may cause high potassium levels if potassium intake is too high. Do not take potassium supplements, follow a diet rich in potassium, or use salt substitutes containing potassium while taking spironolactone. People with reduced kidney function, seniors, and people with Diabetes are more at risk of developing high potassium levels.

Fluid and electrolyte balance: Spironolactone may cause the levels of electrolytes such as potassium, sodium, and chloride in the blood to change while taking this medication. If you experience symptoms of fluid and electrolyte imbalance such as muscle pains or cramps; dry mouth; numb hands, feet, or lips; or racing heartbeat, contact your doctor as soon as possible. Your doctor will do blood tests regularly to monitor the levels of these electrolytes in your blood while you are taking Spironolactone.

Liver function: Small changes to electrolytes and fluid in the body can cause large changes to liver function. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Spironolactone, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking Spironolactone.

Pregnancy: Spironolactone crosses the placenta and may affect the developing baby if taken by a woman when she is pregnant. Spironolactone should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Spironolactone talk to your doctor about the potential benefits and risks of taking Spironolactone during pregnancy.

Spironolactone belongs to the class of medications known as diuretics (water pills). It is used to treat edema (fluid retention) that occurs with Congestive Heart Failure, cirrhosis of the liver, and nephrotic syndrome. It is also used to treat high blood pressure and to diagnose and treat primary hyperaldosteronism (a condition where too much aldosterone is produced by the adrenal glands).

Spironolactone can also be used to treat or prevent hypokalemia (too little potassium in the body) when other methods are not appropriate. Spironolactone works by making the body lose excess water and salt but reduces the loss of potassium from the body.

Spironolactone may be available under multiple brand names and/or in several different forms. Any specific brand name of Spironolactone may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of Spironolactone may not be used for all of the conditions discussed here.

Your doctor may have suggested Spironolactone for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking Spironolactone, speak to your doctor. Do not stop taking Spironolactone without consulting your doctor.

Do not give Spironolactone to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take Spironolactone if their doctor has not prescribed it.