Overdose can manifest itself in the form of nausea and vomiting, and (more rarely) by drowsiness, confusion, skin rash or diarrhoea.
In addition, infertility can occur at very high doses (450 mg/day).
Hyponatraemia, or hyperkalaemia may be induced , but these effects are unlikely to be associated with acute overdosage. Symptoms of hyperkalaemia may manifest as paraesthesia, weakness, flaccid paralysis or muscle spasm and may be difficult to distinguish clinically from hypokalaemia. Electrocardiographic changes are the earliest specific signs of potassium disturbances. No specific antidote has been identified. Improvement may be expected after withdrawal of the drug.
If electrolyte balance disturbance and dehydration occur,treatment is symptomatic and supportive and may include replacement of fluids and electrolytes may be indicated. For hyperkalaemia, reduce potassium intake, administer potassium-excreting diuretics, intravenous glucose with regular insulin or oral ion-exchange resins.
- Severe renal insufficiency (eGFR <30 mL per minute per 1.73 m2), acute or progressive kidney disease (whether or not this is accompanied by anuria)
- Hyponatraemia
- Hyperkalaemia (serum potassium level > 5.0 mmol/L) at initiation
- Concomitant use of potassium-sparing diuretics (including eplerenone) or potassium-supplements, or dual-RAAS blockade with the combination of an angiotensin converting enzyme (ACE) inhibitor and an angiotensin receptor blocker (ARB)
Uractone is contraindicated in paediatric patients with moderate to severe renal impairment.
Not applicable.
The undesirable effects are dependent on dose and duration of treatment.
The most common adverse effects are hyperkalaemia (9%), disorders of the reproductive system and breasts, including gynaecomastia, reported in 13% of patients (at a dose of less than 100 mg).)
Common: hyponatraemia (in particular during combined intensive therapy with thiazide diuretics), hyperkalaemia in (1) patients with severe renal dysfunction, (2) patients receiving treatment with ACE inhibitors or potassium chloride, (3) the elderly, and (4) diabetic patients
Uncommon: acidity of the blood (acidosis) in patients with liver problems
Rare: insufficient fluid in the tissues (dehydration), porphyria, temporary increase in nitrogen levels in the blood and urine, hyperuricemia (may lead to gout in predisposed patients)
Not known: reversible hyperchloraemic metabolic acidosis - usually accompanied by hyperkalaemia has been reported in some patients with decompensated hepatic cirrhosis, even where renal function was normal.
Psychiatric disorders
Uncommon: confusion
Nervous system disorders
Very common: headache
Common: weakness, lethargy in patients with cirrhosis, tingling (paraesthesia)
Rare: paralysis, paraplegia of the limbs due to hyperkalaemia
Not known: dizziness, ataxia
Vascular disorders
Very rare: inflammation of the vessel walls (vasculitis)
Not known: mild hypotension
Gastrointestinal disorders
Very common: indigestion, diarrhoea
Common: nausea and vomiting
Very rare: gastric inflammation, gastric ulcers, intestinal haemorrhage, cramps
Hepatobiliary disorders
Very rare: hepatitis
Skin and subcutaneous tissue disorders
Uncommon: skin rash, urticaria, erythema, chloasma, pruritus, exanthema
Very rare: alopecia, eczema, erythema annulare centrifugum (EAC), hypertrichosis
Not known: Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug rash with eosinophilia and systemic symptoms (DRESS), Pemihigoid
Musculoskeletal and connective tissue disorders
Uncommon: muscle spasms, leg cramps
Very rare: systemic lupus erythematosus (SLE), Osteomalacia
Renal and urinary disorders
Uncommon: elevated serum creatinine levels
Very rare: acute renal failure
Reproductive system and breast disorders
Very common: Men: reduced libido, erectile dysfunction, impotence, enlargement of the mammary glands (gynaecomastia);
Women: breast disorders, tenderness of the breasts, menstrual disorders, deepening of the voice (in many cases irreversible)
Common: Women: changes in vaginal secretions, reduced libido, absence of periods (amenorrhoea), post-menopausal bleeding
General disorders and administration site conditions
Very common: fatigue, drowsiness
common: malaise
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via
Yellow Card Scheme
Website: www.mhra.gov.uk/yellowcard.
Preclinical data do not add relevant information to that already mentioned in other sections of this SmPC.
Uractone has been shown to be tumourigenic in rats when administered at high doses over a long period of time. The significance of these findings with respect to clinical use is not known.
Studies on reproduction toxicity have not shown an increased risk of congenital anomalies, but an anti-androgenic effect in rat offspring has raised concern about possible adverse effects on male genital development. There is no confirmation in humans of these possible adverse effects.
- Oedema associated with congestive heart failure
- Severe heart failure, (NYHA III-IV)
- As an adjuvant in treatment of resistant hypertension
- Nephrotic syndrome
- Liver cirrhosis with ascites and oedema
- Diagnosis and treatment of primary hyperaldosteronism (Conn's syndrome)
Children should only be treated under guidance of a paediatric specialist. There is limited paediatric data available
Pharmacotherapeutic group: cardiovascular system, diuretics, potassium-sparing diuretics, aldosterone antagonist.
ATC code: C03DA01
Uractone affects the kidney and the adrenal gland (as an antagonist of aldosterone in the renal tubuli and an inhibitor of aldosterone synthesis in high concentrations).
Uractone promotes diuresis in patients with oedema or ascites by increasing excretion of sodium in the urine. Potassium loss caused by thiazide diuretics is reduced. It has a gradual and prolonged action.
The antihypertensive effect of Uractone is based on water and salt depletion.
Severe heart failure: RALES
The Randomized Aldactone Evaluation Study (RALES) was a multinational, double-blind study in 1663 patients with an ejection fraction of ≤ 35%, a history of New York Heart Association (NYHA) class IV heart failure within 6 months, and class III-IV heart failure at the time of randomisation. All patients were taking a loop diuretic, 97% were taking an ACE inhibitor and 78% were on digoxin (at the time this trial was conducted, beta-blockers were not widely used to treat heart failure and only 15% were treated with a beta-blocker). Patients with a baseline serum creatinine of >2.5 mg/dL or a recent increase of 25% or with a baseline serum potassium of >5.0 mEq/L were excluded. Patients were randomized 1:1 to Uractone 25 mg orally once daily or matching placebo. Patients who tolerated 25 mg once daily had their dose increased to 50 mg once daily as clinically indicated. Patients who did not tolerate 25 mg once daily had their dosage reduced to 25 mg every other day. The primary endpoint for RALES was time to all-cause mortality. RALES was terminated early, after a mean follow-up of 24 months, because of a significant mortality benefit detected on a planned interim analysis. Uractone reduced the risk of death compared to placebo (mortality Uractone 284/841 (35%); placebo 386/822 (46%); Risk reduction 30% ; 95% confidence interval 18% to 40%; p<0.001). Uractone also significantly reduced the risk of cardiac death, primarily sudden death and death from progressive heart failure as well as the risk of hospitalization for cardiac causes.
Paediatric population
There is a lack of substantive information from clinical studies on Uractone in children. This is a result of several factors: the few trials that have been performed in the paediatric population, the use of Uractone in combination with other agents, the small numbers of patients evaluated in each trial and the different indications studied. The dosage recommendations for paediatrics are based upon clinical experience and case studies documented in scientific literature.
Absorption
Approximately 70% of Uractone is absorbed after oral administration. The bioavailability of Uractone can be increased if it is taken with food. The clinical relevance of this effect is however not entirely clear. Following the administration of 100 mg of Uractone daily for 15 days in non-fasted healthy volunteers, time to peak plasma concentration (tmax), peak plasma concentration (Cmax), and elimination half-life (t1/2) for Uractone is 2.6 hr., 80ng/ml, and approximately 1.4hr., respectively. For the 7-alpha- (thiomethyl) Uractone and canrenone metabolites, tmax was 3.2 hr. and 4.3 hr., Cmax was 391 ng/ml and 181 ng/ml, and t1/2 was 13.8 hr. and 16.5 hr, respectively.
Distribution
Both Uractone and canrenone are over 90% bound to plasma proteins.
Biotransformation
Uractone is extensively metabolised to active metabolites: including thiomethyl- Uractone and canrenone.
Elimination
The plasma half-life of Uractone is approximately 1.5 hours, that of 7-thiomethyl- Uractone approximately 9-12 hours and that of canrenone 10-35 hours. Elimination of metabolites occurs primarily in the urine and secondarily through biliary excretion in the faeces. The renal action of a single dose of Uractone reaches its peak after 7 hours, and activity persists for at least 24 hours
Paediatric population
There are no pharmacokinetic data available in respect of use in paediatric population. The dosage recommendations for paediatrics are based upon clinical experience and case studies documented in the scientific literature.
Fluid and electrolyte balance
During long-term therapy with Uractone, fluid and and electrolyte status should be regularly monitored, especially in elderly patients. Administration of Uractone is not recommended if plasma potassium levels are elevated and contra-indicated in severe renal insufficiency During treatment with Uractone, severe hyperkalaemia can occur, which may result in cardiac arrest (sometimes fatal) in patients with severe renal dysfunction who are receiving concomitant treatment with potassium supplements.
Hyperkalaemia may be accompanied by paraesthesia, weakness, mild paralysis or muscle spasms and is difficult to distinguish clinically from hypokalaemia. ECG changes may be the first sign of disturbed potassium balance, although hyperkalaemia is not always accompanied by an abnormal ECG.
Combination with potent potassium-sparing diuretics such as triamterene and amiloride is contra-indicated in order to prevent hyperkalaemia and care should be taken to avoid administration of extra potassium
Impaired renal function
Potassium levels should be monitored regularly in patients with impaired renal function, including diabetic microalbuminuria. The risk of hyperkalaemia increases with decreasing renal function. Therefore, these patients should be treated with caution.
Severe hepatic insufficiency
Caution is required in patients with hepatic disorders due to the risk of hepatic coma.
Carcinogenicity
Animal studies have shown that at high doses and after long-term use, Uractone induces tumours. The significance of these data for clinical application is unclear. However, the benefits of therapy should be weighed against the possible long-term harm before initiating long-term use of Uractone in young patients.
Lactose
This medicine contains lactose. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Paediatric population
Potassium-sparing diuretics should be used with caution in hypertensive paediatric patients with mild renal insufficiency because of the risk of hyperkalaemia..
Concomitant use of medicinal products known to cause hyperkalaemia with Uractone may result in severe hyperkalaemia.
No data are available on the ability to drive. Undesirable effects such as dizziness, confusion and headache may occur. The possible occurrence of these undesirable effects should be taken into account when driving or using machines.
Posology
Adults
The dosage should be determined individually depending on the condition and the degree of diuresis required. Dosage up to100 mg daily may be administered as a single dose or in divided doses.
Oedema associated with congestive heart failure
For management of oedema an initial daily dose of 100 mg of Uractone administered in either single or divided doses is recommended, but may range from 25 to 200 mg daily. Maintenance dose should be individually determined.
Severe heart failure (NYHA Class III-IV)
Treatment in conjunction with standard therapy should be initiated at a dose of Uractone 25 mg once daily if serum potassium is ≤ 5.0 mEq/L and serum creatinine is ≤ 2.5 mg/dL (221 µmol/L).
Resistent Hypertension
The starting dose for Uractone should be 25mg daily in a single dose; the lowest effective dose should be found, very gradually titrating upwards to a dose of 100mg daily or more.
Nephrotic syndrome
Usual dose is 100-200mg/day. Uractone has not been shown to be anti-inflammatory, nor to affect the basic pathological process. Its use is only advised if glucocorticoids by themselves are insufficiently effective.
Hepatic cirrhosis with ascites and oedema
The starting dose is 100-200 mg per day, e.g. based on Na+/K+ ratio. If the response to 200 mg Uractone within the first two weeks is not sufficient, furosemide is added and if necessary, the Uractone dose is increased stepwise up to 400 mg per day. Maintenance dosage should be individually determined.
Diagnosis and treatment of primary aldosteronism
If primary hyperaldosteronism is suspected, Uractone is given at a dose of 100 - 150 mg, or up to 400 mg daily. In the event of rapid onset of a strong diuretic and antihypertensive effect, this is a clear indication of elevated aldosterone production. In this case, 100 - 150 mg daily is administered for 3 - 5 weeks prior to surgery. If surgery is not an option, this dose is often sufficient to maintain blood pressure and potassium concentration at normal levels. In exceptional cases, higher doses are necessary, but the lowest possible dosage should be found.
Paediatric population
Initial daily dosage should provide 1-3 mg of Uractone per kilogram body weight, given in divided doses. Dosage should be adjusted on the basis of response and tolerance. The tablet may be ground or crushed and then suspended in water to make it easier to take.
Children should only be treated under guidance of a paediatric specialist. There is limited paediatric data available.
The Elderly
It is recommended that treatment is started at the lowest possible dose, then titrated with higher doses until the optimum effect is achieved. Caution is required, in particular in renal dysfunction.
Method of administration
The tablets should be taken with meals. Daily dosages in excess of 100 mg should be given in several divided doses.
Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
