Side Effects of This Medicine

In rats, spironolactone has been found to increase the risk of development of tumors. However, the doses given were many times the dose of spironolactone given to humans. It is not known whether spironolactone causes tumors in humans.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

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

Rare

Black, tarry stools; blood in urine or stools; cough or hoarseness; fever or chills; joint pain; lower back or side pain; painful or difficult urination; pinpoint red spots on skin; skin rash or hives; stomach pain (severe) with nausea and vomiting; unusual bleeding or bruising; yellow eyes or skin

Signs and symptoms of changes in potassium

Confusion; dryness of mouth; increased thirst; irregular heartbeat; mood or mental changes; muscle cramps or pain; numbness or tingling in hands, feet, or lips; shortness of breath or difficulty breathing; unusual tiredness or weakness; weak pulse; weakness or heaviness of legs

Reported for triamterene only (rare)

Bright red tongue; burning, inflamed feeling in tongue; cracked corners of mouth

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

More common (less common with triamterene)

Loss of appetite; nausea and vomiting; stomach cramps and diarrhea; upset stomach

Less common

Decreased sexual ability; dizziness or lightheadedness when getting up from a lying or sitting position; headache; increased sensitivity of skin to sunlight

Reported for amiloride only (less common)

Constipation

Reported for spironolactone only (less common)

Breast tenderness in females; deepening of voice in females; enlargement of breasts in males; increased hair growth in females; irregular menstrual periods; sweating

Spironolactone sometimes causes enlarged breasts in males, especially when they take large doses of it for a long time. Breasts usually decrease in size gradually over several months after this medicine is stopped. If you have any questions about this, check with your doctor.

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.