Loading...
Loading...
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Brand Name
Aldactone
Generic Name
Spironolactone
Active Ingredient
SpironolactoneCategory
Aldosterone Antagonist [EPC]
Variants
3
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Aldactone, you must consult a qualified healthcare professional.
Detailed information about Aldactone
Spironolactone is a potassium-sparing diuretic and aldosterone antagonist used to treat heart failure, hypertension, and edema by blocking salt-retaining hormones.
The dosage of spironolactone varies significantly depending on the condition being treated. Healthcare providers will typically start with a low dose and titrate upward based on the patient's response and tolerance.
Spironolactone is used in pediatric populations, though it is not FDA-approved for all the same indications as adults. Pediatric dosing is strictly weight-based. The typical range is 1 mg to 3 mg per kilogram of body weight per day, divided into two to four doses. Healthcare providers must exercise extreme caution in children, as they may be more susceptible to electrolyte imbalances.
Renal function is the most critical factor in spironolactone dosing. For patients with a Glomerular Filtration Rate (GFR) between 30 and 50 mL/min, doses should be reduced (e.g., 25 mg every other day for heart failure). Spironolactone is generally contraindicated in patients with severe renal impairment (GFR < 30 mL/min) or acute renal failure due to the extreme risk of life-threatening hyperkalemia (high potassium).
In patients with cirrhosis or liver dysfunction, spironolactone must be introduced slowly. Sudden changes in fluid balance can precipitate hepatic encephalopathy (a decline in brain function due to liver disease).
Older adults are at a higher risk for both renal decline and hyperkalemia. Clinical guidelines suggest starting at the lowest possible dose and performing frequent blood tests to monitor potassium and creatinine levels.
If you miss a dose, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and resume your regular schedule. Never double the dose to 'catch up,' as this significantly increases the risk of hyperkalemia.
Signs of a spironolactone overdose include extreme drowsiness, mental confusion, a maculopapular or erythematous rash, nausea, vomiting, or diarrhea. The most dangerous consequence of overdose is severe hyperkalemia, which can cause muscle weakness, paresthesia (tingling), and cardiac arrhythmias. In the event of a suspected overdose, contact your local poison control center or seek emergency medical attention immediately.
> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose or stop taking the medication without medical guidance, as this could lead to a rapid rebound in fluid retention or blood pressure.
Spironolactone is generally well-tolerated, but its hormonal and electrolyte effects lead to several common side effects.
Spironolactone is a potent medication that requires careful medical supervision. The most critical safety concern is the risk of hyperkalemia (dangerously high blood potassium levels). If left unmonitored, hyperkalemia can lead to fatal cardiac arrhythmias. Patients must be educated on the symptoms of high potassium and the importance of adhering to lab testing schedules.
As of the most recent FDA updates in 2024, spironolactone does not currently carry a prominent Black Box Warning for acute human toxicity, but historical labels emphasized that the drug was shown to be a tumorigen in chronic toxicity studies in rats. Healthcare providers are advised to use the drug only for indicated conditions and to avoid off-label use where safer alternatives exist.
Spironolactone must NEVER be used in patients with the following conditions:
Spironolactone is generally classified as Pregnancy Category C or D depending on the specific international guideline. The primary concern is its anti-androgenic mechanism of action. Animal studies have shown that exposure to spironolactone during pregnancy can cause the feminization of male fetuses (interference with male genital development). While there are no well-controlled studies in pregnant women, the American College of Obstetricians and Gynecologists (ACOG) generally recommends against its use for acne or hypertension during pregnancy. If a patient becomes pregnant while taking spironolactone, they should contact their doctor immediately.
Canrenone, the primary active metabolite of spironolactone, is excreted in human breast milk in very small amounts. According to the American Academy of Pediatrics, spironolactone is generally considered compatible with breastfeeding. However, because it is a diuretic, it may theoretically decrease milk production if the mother becomes dehydrated. Nursing infants should be monitored for any unusual symptoms, though the risk of adverse effects is considered low.
Spironolactone is used in children primarily for the management of heart failure or hypertension related to kidney disease. It is not FDA-approved for acne in adolescents, though it is commonly used off-label. The main concern in children is the risk of hyperkalemia and potential interference with pubertal development due to its hormonal effects. Long-term studies on growth and development in children taking spironolactone are limited.
Spironolactone is a specific pharmacologic antagonist of aldosterone, acting primarily through competitive binding of receptors at the aldosterone-dependent sodium-potassium exchange site in the distal convoluted renal tubule. Aldosterone normally binds to mineralocorticoid receptors (MR), which then translocate to the nucleus to promote the expression of ENaC (Epithelial Sodium Channels). By blocking this process, spironolactone prevents sodium reabsorption. Furthermore, spironolactone has modest anti-androgenic activity by competitively inhibiting the binding of testosterone and dihydrotestosterone (DHT) to their receptors.
The onset of the diuretic effect of spironolactone is gradual, with peak effects usually occurring 2 to 3 days after treatment is initiated. Similarly, when the drug is discontinued, the effects may persist for 2 to 3 days. This delayed action is because the drug works by changing protein expression (sodium channels) rather than directly blocking a channel. Spironolactone does not interfere with the mechanism of sodium transport in the proximal tubule or the loop of Henle.
| Parameter | Value |
Common questions about Aldactone
Spironolactone is primarily used to treat fluid retention (edema) caused by heart failure, liver cirrhosis, or kidney disease. It is also an effective treatment for high blood pressure, particularly when other medications are not sufficient. Additionally, it is used to treat primary hyperaldosteronism, a condition where the body produces too much of the hormone aldosterone. Off-label, healthcare providers frequently prescribe it for hormonal acne and excessive hair growth in women. It works by blocking the effects of salt-retaining hormones and androgens.
The most frequent side effects include high potassium levels (hyperkalemia), which can be serious if not monitored. Men may experience breast tissue swelling or tenderness, known as gynecomastia, due to the drug's hormonal effects. Women often report menstrual irregularities, such as spotting or missed periods. Other common issues include dizziness, headache, and stomach upset. Most side effects are dose-dependent and may resolve if the dose is adjusted by a doctor.
It is generally advised to limit or avoid alcohol while taking spironolactone. Alcohol can increase the blood-pressure-lowering effects of the medication, which may lead to severe dizziness, lightheadedness, or fainting. This risk is especially high when standing up quickly from a sitting or lying position. Furthermore, alcohol can contribute to dehydration, which increases the strain on the kidneys while taking a diuretic. Always consult your healthcare provider about your specific alcohol consumption habits.
Spironolactone is generally not recommended during pregnancy because it has anti-androgenic properties that could interfere with the normal development of a male fetus. Specifically, animal studies have shown it can cause the feminization of male offspring. Most healthcare providers advise women to stop taking the medication if they are planning to become pregnant or as soon as pregnancy is confirmed. If you are taking it for acne or blood pressure, your doctor will likely switch you to a safer alternative. Always discuss pregnancy planning with your medical team.
The timeline for spironolactone's effectiveness depends on the condition being treated. For fluid retention and blood pressure, you may notice increased urination within 24 hours, but the full therapeutic effect often takes 3 to 5 days to develop. If you are taking it for hormonal acne, the results are much slower; it typically takes 8 to 12 weeks of consistent use to see a significant improvement in skin clarity. Because it works by altering hormone receptors and protein expression, patience is required during the initial phase of treatment.
You should not stop taking spironolactone suddenly without consulting your healthcare provider. For patients with heart failure or high blood pressure, abrupt discontinuation can lead to a rapid rebound in fluid retention and a dangerous spike in blood pressure levels. If the medication needs to be stopped due to side effects, your doctor will usually provide a tapering schedule or immediately start a different medication. Always follow professional medical advice when changing your dosing regimen.
If you miss a dose, take it as soon as you remember. If it is nearly time for your next scheduled dose, skip the missed one and continue with your regular timing. You should never take two doses at once to make up for a missed one, as this significantly increases the risk of hyperkalemia (high potassium). Consistency is key to the drug's effectiveness, so try to take it at the same time each day. If you frequently miss doses, consider using a pill organizer or alarm.
Spironolactone is more likely to cause weight loss than weight gain because it is a diuretic that helps the body eliminate excess water weight. Many patients with heart failure or edema notice a drop in weight as their swelling subsides. However, in rare cases, some women report minor changes in fat distribution or breast enlargement due to the drug's effect on estrogen and androgen balance. If you notice rapid, unexplained weight gain, it may actually be a sign that your heart failure is worsening, and you should contact your doctor immediately.
Spironolactone has several significant drug interactions, particularly with other medications that affect potassium levels. Taking it with ACE inhibitors, ARBs, or potassium supplements can lead to dangerously high potassium. It can also interact with NSAIDs like ibuprofen, which may reduce its effectiveness and harm the kidneys. It is vital to provide your doctor and pharmacist with a complete list of all prescription drugs, over-the-counter medicines, and herbal supplements you are taking. Regular blood tests are usually required when combining spironolactone with other heart or blood pressure medications.
Yes, spironolactone is widely available as a low-cost generic medication in tablet form. The generic versions are considered bioequivalent to the brand-name drug Aldactone. There is also a brand-name oral suspension called CaroSpir for those who cannot swallow tablets, which may be more expensive. Most insurance plans cover the generic tablets. Because it is an older, well-established medication, it is generally one of the more affordable options for managing hypertension and heart failure.
Other drugs with the same active ingredient (Spironolactone)
> Warning: Stop taking Spironolactone and call your doctor immediately if you experience any of these serious symptoms:
Prolonged use of spironolactone requires vigilance regarding endocrine and renal health. Long-term effects may include:
Historically, spironolactone carried a boxed warning regarding tumorigenicity based on high-dose studies in rats. However, in recent years, the FDA has modified these requirements as human clinical data has not demonstrated a definitive link between therapeutic doses of spironolactone and cancer. Nevertheless, the drug should only be used for its approved indications and unnecessary use should be avoided.
Report any unusual symptoms to your healthcare provider. Regular blood work is the only way to ensure that the medication is not causing 'silent' side effects like high potassium or kidney strain.
To ensure patient safety, healthcare providers typically require the following monitoring schedule:
Spironolactone may cause drowsiness or dizziness, especially during the first few days of treatment or after a dose increase. Patients should observe how the medication affects them before driving or operating heavy machinery. If you feel lightheaded, sit or lie down immediately.
Alcohol can exacerbate the blood-pressure-lowering effects of spironolactone, leading to a higher risk of fainting, dizziness, and falls. It is generally recommended to limit or avoid alcohol consumption while taking this medication.
Abruptly stopping spironolactone in patients with heart failure or severe hypertension can lead to a rapid return of edema or a 'rebound' spike in blood pressure. If the drug must be stopped, healthcare providers usually recommend a tapering schedule while monitoring for signs of fluid retention.
> Important: Discuss all your medical conditions, including kidney disease, liver disease, and diabetes, with your healthcare provider before starting Spironolactone.
Spironolactone can interfere with the measurement of serum digoxin and may also affect the results of certain cortisol tests. Always inform laboratory personnel that you are taking this medication.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking. A complete medication review is the best way to prevent dangerous interactions.
Conditions requiring a careful risk-benefit analysis by a healthcare provider include:
There is no significant evidence of cross-sensitivity between spironolactone and other classes of diuretics like thiazides or loops. However, patients with a history of severe drug rashes should be monitored closely when starting any new steroidal medication.
> Important: Your healthcare provider will evaluate your complete medical history, including recent lab results, before prescribing Spironolactone.
Older adults (65+) are the most frequent users of spironolactone for heart failure. However, they are at the highest risk for adverse effects. Age-related decline in kidney function (reduced GFR) makes hyperkalemia much more likely. Additionally, the risk of orthostatic hypotension (dizziness when standing) is higher in the elderly, which can lead to hip fractures and other fall-related injuries. Clinical guidelines recommend 'starting low and going slow' with dosing in this population.
In patients with mild to moderate renal impairment (GFR 30-50 mL/min), spironolactone must be used with extreme caution. Doses should be halved or given every other day. If the GFR drops below 30 mL/min, the drug should generally be discontinued. Spironolactone is not effectively removed by hemodialysis, so patients on dialysis require specialized management of their potassium levels.
In patients with liver disease, spironolactone is often used to treat ascites (fluid in the abdomen). However, these patients are prone to rapid electrolyte shifts. Treatment should ideally be initiated in a hospital setting where electrolytes and mental status can be monitored daily to prevent hepatic encephalopathy.
> Important: Special populations require individualized medical assessment and more frequent laboratory monitoring than the general population.
| Bioavailability | >90% (increased with food) |
| Protein Binding | >90% (primarily albumin) |
| Half-life | 1.4 hours (Parent); 13-24 hours (Metabolites) |
| Tmax | 1-3 hours |
| Metabolism | Hepatic (CYP3A4); Active metabolites: Canrenone, 7-alpha-thiomethylspironolactone |
| Excretion | Renal 40-60%, Fecal/Biliary 40-50% |
Spironolactone belongs to the therapeutic class of Aldosterone Antagonists (also known as Mineralocorticoid Receptor Antagonists or MRAs). It is also classified as a Potassium-Sparing Diuretic. Related medications include eplerenone (Inspra) and the newer non-steroidal agent finerenone (Kerendia).