Source: Marketing Authorisation Holder Revision Year: 2022 Publisher: Alphapharm Pty Ltd trading as Viatris, Level 1, 30 The Bond, 30-34 Hickson Road, Millers Point NSW 2000, www.viatris.com.au, Phone: 1800 274 276
Essential hypertension. Spironolactone, when used alone, is effective in lowering both systolic and diastolic blood pressure. Spironolactone improves the hypotensive action of thiazide diuretics, while at the same time reducing or preventing potassium loss due to the thiazide. Spironolactone enhances the effectiveness of other antihypertensive agents such as β-blockers, vasodilators, etc.
As adjunctive therapy in malignant hypertension.
In diuretic-induced hypokalaemia when other measures are considered inappropriate or inadequate.
Prophylaxis of hypokalaemia in patients taking digitalis when other measures are considered inadequate or inappropriate.
Congestive cardiac failure. When used alone, spironolactone is effective in the management of oedema and sodium retention associated with congestive cardiac failure. Spironolactone may be used in combination with a thiazide or other conventional diuretics for achieving diuresis in patients whose oedema is resistant to a thiazide or other conventional diuretics. Unlike conventional diuretics, spironolactone does not produce hypokalaemia. When administered with a thiazide or other conventional diuretics, spironolactone offsets hypokalaemia induced by these diuretics. The prevention of potassium loss is particularly important in the treatment of digitalised patients since digitalis intoxication may be precipitated if hypokalaemia is induced by conventional diuretic therapy.
Hepatic cirrhosis with ascites and oedema. When used alone, spironolactone is frequently adequate for the relief of ascites and oedema associated with hepatic cirrhosis. It provides a mild and even diuresis and prevents excessive potassium excretion caused by thiazide diuretics, thus avoiding possible precipitation of hepatic coma.
Nephrotic syndrome. Although glucocorticoids, whose anti-inflammatory activity appears to benefit the primary pathological process in the renal glomerulus, should probably be employed first, spironolactone either alone or in combination with a conventional diuretic is useful for inducing diuresis.
Diagnosis and treatment of primary hyperaldosteronism. Spironolactone may be used to establish the diagnosis of primary hyperaldosteronism by therapeutic trial. Spironolactone may also be used for the short-term preoperative treatment of patients with primary hyperaldosteronism, long-term maintenance therapy for patients with discrete aldosterone producing adrenal adenomas who are judged to be poor operative risks (or who decline surgery), and long-term maintenance therapy for patients with bilateral micro- or macronodular adrenal hyperplasia (idiopathic hyperaldosteronism).
Hirsutism in females. Spironolactone is effective in the treatment of females with hirsutism, an androgen related increase in facial and body hair. A reduction in hair growth, hair shaft diameter and hair pigmentation is seen.
Use of SPIRACTIN should be considered only after all other alternatives of non-drug therapy have been explored. For women of childbearing age, see Section 4.3 CONTRAINDICATIONS and Section 4.6 FERTLITY, PREGNANCY AND LACTATION – Use in Pregnancy.
50 to 100 mg/day which may be given either in divided doses or as a single daily dose.
Dosage should be adjusted according to response, but it should be noted that maximum effect of spironolactone therapy may not occur for up to two weeks after starting treatment.
Spironolactone may potentiate the action of diuretics or other antihypertensive drugs, and their dosage should first be reduced by at least 50% when SPIRACTIN is added to the regimen, and then adjusted as necessary.
The daily dose may be given either in divided doses or as a single daily dose.
Congestive cardiac failure: The initial dose is 100 mg/day. In difficult or severe cases, the dosage may be gradually increased up to 200 mg/day. When oedema is controlled, the usual maintenance level is 25 to 200 mg/day.
Cirrhosis: If the urinary sodium/potassium ratio is greater than one, the recommended dose is 100 mg/day. If the ratio is less than one, the recommended dose is 200 to 400 mg/day. Maintenance dosage should be individually determined.
Nephrotic syndrome: Usually 100 to 200 mg/day. Spironolactone is not anti-inflammatory, has not been shown to affect the basic pathological process and its use is only advised when treatment of the underlying disease, restriction of fluid intake and sodium intake, and the use of other diuretics do not provide an adequate response.
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 hypokalaemia 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 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, SPIRACTIN 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.
Spironolactone should be used as adjunctive therapy only, where there is an excessive secretion of aldosterone, hypokalaemia and metabolic alkalosis. The initial dosage is 100 mg/day increased as necessary in two weekly intervals to 400 mg/day. Initial therapy should include a combination of other antihypertensive drugs and spironolactone. Do not automatically reduce the dose of other treatments as is recommended for essential hypertension.
Spironolactone may be useful in treating diuretic-induced hypokalaemia when oral potassium supplements are considered inappropriate. In treating hypokalaemia, the lowest dose should be used and titrated upwards. A daily dose exceeding 100 mg is not recommended.
100 to 200 mg/day in divided doses is usual, however 50 mg daily has also been shown to be effective.
Clinical improvement is usually shown within 3 to 6 months and an initial course of treatment should continue for 12 months.
Spironolactone may be administered continuously or as a cyclical dosage for approximately three weeks out of every four weeks. Dosing from day 5 to 21 of the menstrual cycle, with a drug free interval during menstruation, has been effective. Cyclical dosing may reduce menstrual irregularities in women with previously regular cycles.
Combined use with estrogen progestogen oral contraceptives may also be considered to provide both regular menstrual cycles and adequate contraception (see Section 4.6 FERTILITY, PREGNANCY AND LACTATION – Use in Pregnancy).
The initial daily dosage should provide approximately 3.3 mg spironolactone/kg bodyweight. For small children, spironolactone tablets may be pulverised and administered as a suspension in cherry syrup. When refrigerated, such a suspension is stable for one month.
Overdosage may be manifested by nausea and vomiting, dizziness and (more rarely) by drowsiness, mental confusion, maculopapular or erythematous rash or diarrhoea. Electrolyte imbalances and dehydration may occur. Hyperkalaemia may be produced; symptoms include paraesthesia, weakness, flaccid paralysis and tetany. The earliest signs are characteristic electrocardiographic abnormalities including tall ‘tent shaped’ T waves, decreased amplitude of the P waves and widening of the QRS complex. Delayed onset of hyperkalaemia has been reported after acute ingestion of spironolactone (peak levels at 24 and 32 hours).
Symptomatic and supportive measures should be employed. There is no specific antidote. Support respiratory and cardiac functions. Treat fluid depletion, electrolyte imbalances and hypotension by established procedures.
Severity of intoxication should be based on clinical findings and serial determination of serum potassium levels. Monitoring plasma levels of spironolactone is not clinically useful.
Hyperkalaemia can be treated promptly by the rapid intravenous administration of glucose (20 to 50%) and regular insulin, using 0.25 to 0.5 units of insulin per g of glucose. Potassium excreting diuretics and ion exchange resins may also be administered and repeated as required.
SPIRACTIN should be discontinued and potassium intake (including dietary potassium) restricted.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).
In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.
Store below 30°C. This medicinal product does not require any special storage conditions.
Container Type: HDPE bottles with PP cap – Child Resistant Closure.
Pack Size: 100 tablets.
AUST R 46689 – SPIRACTIN 25 spironolactone 25mg tablet bottle.
AUST R 46691 – SPIRACTIN 100 spironolactone 100mg tablet bottle.
In Australia, any unused medicine or waste material should be disposed of by taking it to your local pharmacy.
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