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 Aldactone (Spironolactone). If you are concerned about side effects, discuss the risks and benefits of Aldactone (Spironolactone) with your doctor.

The following side effects have been reported by at least 1% of people taking Aldactone (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 light yellow, round, biconvex, film-coated tablet, debossed "ALDACTONE" and "25" on one face and "SEARLE" and "1001" on the other face and with peppermint odour, contains Aldactone (Spironolactone) 25 mg. Nonmedicinal ingredients: calcium sulfate, carnauba wax, cornstarch, hypromellose, magnesium stearate, opaspray M-1-2042, peppermint flavouring, polyethylene glycol 400, povidone, and stearic acid.

100 mg
Each peach, round, biconvex, scored, film-coated tablet, debossed "ALDACTONE" and "100" on one face and "SEARLE" and "1031" on the other (scored) face and with peppermint odour, contains Aldactone (Spironolactone) 100 mg. Nonmedicinal ingredients: calcium sulfate, carnauba wax, cornstarch, hypromellose, magnesium stearate, opaspray M-1-2668, peppermint flavouring, polyethylene glycol 400, povidone, and stearic acid.

Do not take Aldactone (Spironolactone) if you:

• are allergic to Aldactone (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 Aldactone (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 Aldactone (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 Aldactone (Spironolactone).

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

Drowsiness and dizziness: Aldactone (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 Aldactone (Spironolactone) affects you. Aldactone (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: Aldactone (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 Aldactone (Spironolactone). People with reduced kidney function, seniors, and people with Diabetes are more at risk of developing high potassium levels.

Fluid and electrolyte balance: Aldactone (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 Aldactone (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 Aldactone (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 Aldactone (Spironolactone).

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