Common Use
Spironolactone is a potassium-sparing diuretic and aldosterone antagonist widely prescribed for the management of high blood pressure, heart failure, edema (fluid retention), and primary hyperaldosteronism (excess aldosterone production). As a trusted cardiovascular medication, spironolactone works by blocking the effects of the hormone aldosterone in the kidneys, promoting the elimination of excess sodium and water from the body while importantly preserving potassium levels. This unique mechanism makes it a preferred choice among diuretics for patients at risk of hypokalemia. Beyond its cardiovascular uses, spironolactone is also prescribed off-label for hormonal acne, hirsutism (excess hair growth), and polycystic ovary syndrome (PCOS) in women, thanks to its anti-androgen properties. Available under the brand name Aldactone and as an affordable Aldactone generic, spironolactone has been a cornerstone of heart failure and blood pressure management for decades. If you are looking to buy Spironolactone online, this well-established medication offers reliable, physician-trusted relief from fluid retention and hypertension.

Dosage and Direction
Spironolactone is usually taken once or twice daily by mouth, with or without food, although taking it with food may improve absorption and reduce stomach upset. The dosage depends on the specific condition being treated: for blood pressure management, doses typically range from 25 to 100 mg daily; for heart failure, lower doses of 12.5 to 50 mg are common; and for fluid retention due to liver cirrhosis or nephrotic syndrome, doses may be higher as directed by your physician. Your doctor will determine the optimal dose based on your kidney function, electrolyte levels (especially potassium), and clinical response. Do not increase, decrease, or stop the dose without medical advice, as abrupt changes can affect blood pressure control and electrolyte balance. Because spironolactone increases urination, it may be helpful to take the last dose of the day in the late afternoon to avoid nighttime bathroom disruptions.

Precautions
Before starting spironolactone, tell your doctor if you have kidney problems, high potassium levels (hyperkalemia), Addison’s disease (adrenal insufficiency), or liver disease. Regular monitoring of blood pressure, kidney function (creatinine, BUN), and serum electrolyte levels — particularly potassium — is essential during treatment, especially in elderly patients and those taking other medications that affect potassium levels. Avoid taking potassium supplements, using potassium-containing salt substitutes, or consuming excessive amounts of high-potassium foods (such as bananas, oranges, and leafy greens) unless specifically directed by your healthcare provider. Dehydration from illness, excessive sweating, or inadequate fluid intake can increase the risk of side effects. Women of childbearing age should use effective contraception, as spironolactone may have hormonal effects. Inform your doctor about all existing medical conditions before starting therapy.

Contraindications
Spironolactone is contraindicated in patients with hyperkalemia (high potassium levels), severe kidney impairment (anuria or significant renal failure), or Addison’s disease. It should not be used during pregnancy, as it may have anti-androgenic effects on a developing male fetus. Co-administration with eplerenone (another aldosterone antagonist) is contraindicated due to the risk of severe hyperkalemia. Use in combination with other potassium-sparing diuretics (such as amiloride or triamterene) or potassium supplements significantly increases the risk of dangerously elevated potassium levels and potentially life-threatening cardiac arrhythmias. Patients with known hypersensitivity to spironolactone should avoid use.

Possible Side Effects
Common side effects of spironolactone include dizziness, lightheadedness, headache, breast tenderness or enlargement (gynecomastia in men), menstrual irregularities in women, increased urination, fatigue, and gastrointestinal discomfort (nausea, diarrhea, or cramping). These effects are generally dose-dependent and often improve with continued use or dose adjustment. More serious side effects include dangerously high potassium levels (hyperkalemia), which can manifest as irregular heartbeat, muscle weakness, numbness, or tingling. Signs of severe hyperkalemia require immediate medical attention. Other rare but serious effects include severe allergic reactions, liver toxicity, and electrolyte imbalances. Men taking spironolactone long-term may experience gynecomastia (breast enlargement) due to its anti-androgen properties — discuss this with your doctor if it becomes bothersome.

Drug Interaction
Spironolactone may interact with numerous medications that affect potassium levels or blood pressure. ACE inhibitors (such as lisinopril, enalapril) and angiotensin II receptor blockers (ARBs such as losartan, valsartan) can increase the risk of hyperkalemia when combined with spironolactone. NSAIDs (ibuprofen, naproxen) may reduce the diuretic and blood-pressure-lowering effects of spironolactone and also increase hyperkalemia risk. Digoxin levels may be increased by spironolactone, requiring careful monitoring and possible dose adjustment. Lithium excretion may be reduced, leading to elevated lithium levels and potential toxicity. Potassium supplements and potassium-containing salt substitutes should generally be avoided. Always inform your doctor about all medications, supplements, and herbal products you are using before starting or changing your spironolactone regimen.

Missed Dose
If you miss a dose of spironolactone, take it as soon as you remember. If it is close to your next scheduled dose, skip the missed one and return to your regular dosing schedule. Do not take two doses at once, as this could cause a sudden drop in blood pressure or dangerous changes in potassium levels.

Overdose
Overdose of spironolactone may cause drowsiness, confusion, skin rash, nausea, vomiting, diarrhea, or dangerously high potassium levels (hyperkalemia), which can lead to life-threatening cardiac arrhythmias. Severe dehydration and electrolyte imbalance may also occur. Seek emergency medical attention immediately if overdose is suspected. Treatment focuses on managing symptoms, correcting electrolyte imbalances (particularly lowering potassium levels), and providing supportive cardiac care. In severe cases, dialysis may be necessary.

Storage
Store spironolactone at room temperature, between 20°C and 25°C (68°F to 77°F), away from moisture, heat, and direct light. Keep the medication tightly closed in its original container and out of reach of children and pets. Do not store in the bathroom, as humidity can degrade the medication. Do not use spironolactone after the expiration date, and dispose of unused medication according to local pharmaceutical waste guidelines.

Disclaimer

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.