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.
Along with its needing effects, a drug 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 family doctor as soon as possible if any of the following side effects was happen
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
More common side effects may occur that usually don't needed medical attention. These side effects may go away during treat as your body adjusts to the drug. However, check with your family 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 few months after this drug is stopped. If you have any questions about this, check with your family doctor.
More common side effects not listed above may also occur in some diseaseds. If you notice any other problems, check with your family doctor.