Below are the general guidelines for dosing spironolactone. Note that these dosages may be adjusted on a case-by-case basis for individual patients. Always follow your prescribing physician’s instructions for taking Spironolactone.
The following information comes from DailyMed, an FDA label information provider.
What if I miss a dose of Spironolactone?
According to Mayo Clinic, if you miss a dose of spironolactone, take it immediately unless you are closer in time to your next dose. Never double dose.
What if I overdose on Spironolactone?
The oral LD50 of spironolactone is greater than 1000 mg/kg in mice, rats, and rabbits.
Acute overdosage of spironolactone may be manifested by drowsiness, mental confusion, maculopapular or erythematous rash, nausea, vomiting, dizziness, or diarrhea. Rarely, instances of hyponatremia, hyperkalemia, or hepatic coma may occur in patients with severe liver disease, but these are unlikely due to acute overdosage. Hyperkalemia may occur, especially in patients with impaired renal function.
Treatment of overdose: There is no specific antidote. Treatment is supportive to maintain hydration, electrolyte balance, and vital functions.
Patients who have renal impairment may develop spironolactone-induced hyperkalemia. In such cases, spironolactone should be discontinued immediately. With severe hyperkalemia, the clinical situation dictates the procedures to be employed. These may include the intravenous administration of calcium chloride solution, sodium bicarbonate solution and/or the oral or parenteral administration of glucose with a rapid-acting insulin preparation. These are temporary measures to be repeated as required. Cationic exchange resins such as sodium polystyrene sulfonate may be orally or rectally administered. Persistent hyperkalemia may require dialysis.
Dosage and Administration
Spironolactone may be employed as an initial diagnostic measure to provide presumptive evidence of primary hyperaldosteronism while patients are on normal diets.
Long test: Spironolactone is administered at a daily dosage of 400 mg for three to four weeks. Correction of hypokalemia and of hypertension provides presumptive evidence for the diagnosis of primary hyperaldosteronism.
Short test: Spironolactone is administered at a daily dosage of 400 mg for four days. If serum potassium increases during spironolactone administration but drops when spironolactone is discontinued, a presumptive diagnosis of primary hyperaldosteronism should be considered.
After the diagnosis of hyperaldosteronism has been established by more definitive testing procedures, spironolactone may be administered in doses of 100 to 400 mg daily in preparation for surgery. For patients who are considered unsuitable for surgery, spironolactone may be employed for long-term maintenance therapy at the lowest effective dosage determined for the individual patient.
Edema in Adults (congestive heart failure, hepatic cirrhosis, or nephrotic syndrome):
An initial daily dosage of 100 mg of spironolactone administered in either single or divided doses is recommended, but may range from 25 to 200 mg daily. When given as the sole agent for diuresis, spironolactone should be continued for at least five days at the initial dosage level, after which it may be adjusted to the optimal therapeutic or maintenance level administered in either single or divided daily doses. If, after five days, an adequate diuretic response to spironolactone has not occurred, a second diuretic that acts more proximally in the renal tubule may be added to the regimen. Because of the additive effect of spironolactone when administered concurrently with such diuretics, an enhanced diuresis usually begins on the first day of combined treatment; combined therapy is indicated when more rapid diuresis is desired. The dosage of spironolactone should remain unchanged when other diuretic therapy is added.
For adults, an initial daily dosage of 50 to 100 mg of spironolactone administered in either single or divided doses is recommended. Spironolactone may also be given with diuretics that act more proximally in the renal tubule or with other antihypertensive agents. Treatment with spironolactone should be continued for at least two weeks since the maximum response may not occur before this time. Subsequently, dosage should be adjusted according to the response of the patient.
Spironolactone in a dosage ranging from 25 mg to 100 mg daily is useful in treating a diuretic-induced hypokalemia, when oral potassium supplements or other potassium-sparing regimens are considered inappropriate.
Severe Heart Failure in Conjunction with Standard Therapy (NYHA class III – IV):
Treatment should be initiated with spironolactone 25 mg once daily if the patient’s serum potassium is ≤5.0 mEq/L and the patient’s serum creatinine is ≤2.5 mg/dL. Patients who tolerate 25 mg once daily may have their dosage increased to 50 mg once daily as clinically indicated. Patients who do not tolerate 25 mg once daily may have their dosage reduced to 25 mg every other day.
Spironolactone Dose for Acne
If you are looking to take spironolactone for acne, talk to your doctor. Dosage may differ based on an individual’s personal health profile, as well as any other medications they take.
Generic Name: Spironolactone
Class: Aldosterone antagonist, potassium-sparing diuretic
Molecular Formula: C24H32O4S
Substance UNII: 27O7W4T232
What is Spironolactone?
Spironolactone is an aldosterone antagonist and potassium-sparing diuretic. It is often sold under the trade names Aldactone and CaroSpir.
What is Spironolactone Used For?
The FDA has approved spironolactone for the treatment of heart failure, hypertension, edema associated with nephrotic syndrome or hepatic cirrhosis, and primary hyperaldosteronism. People also sometimes use it to treat acne or to promote weight loss.
How Does Spironolactone Work?
Spironolactone works by blocking the activity of aldosterone, a steroid hormone associated with water retention. This fluid retention can cause certain problems to worsen such as kidney, heart, or liver diseases or conditions. Taking this medication causes higher amounts of water and sodium to be eliminated, thereby reducing water retention.
Spironolactone also prevents your body from excreting or getting rid of potassium. Notably, potassium helps reduce water retention through promoting urination and excretion of sodium during urination.
How Long Does It Take for Spironolactone to Work?
The time it takes for this drug to work depends on what it is being used for and other factors, such as the presence of other medical conditions and dosage being taken. A 2012 study found that it generally takes a few weeks for spironolactone to become effective when it is used for treating acne.
Do Not Use Spironolactone If:
There are several situations where this medication may not be the right choice for you. According to the FDA, the following should not use spironolactone:
- Patients with hyperkalemia (high potassium)
- Patients with Addison’s disease (hypocortisolism or adrenal insufficiency)
- Patients who are using eplerenone (Inspra)
Please note that this list may not be complete, and there may be other situations where use of this drug is not advisable.