Trade name(s): Spiractin, Spirotone
Drug Class:Diuretic
Therapeutic use:
Used as a diuretic that spared vit K
Pharmacological action:
At the distal loop it antagonists aldosterone receptors leading to less sodium reabsorption and reduced K+ excretion.
Pharmacokinetics:
- Administration
exceeds 90% when compared to an optimally absorbed solution - Distribution
- Metabolism
Rapidly metabolised 25-30% of the dose is administered to canrenone, the sulphur containing metabolites and spirolactone both contribute to the drug effect - Excretion
Excreted in urine and bile
Indications:
- oedema and ascites in cirrhosis of the liver
- malignant ascites
- nephrotic syndrome
- oedema in congestive heart failure; moderate to severe heart failure
- resistant hypertension
- treatment of primary hyperaldosteronism
- hirsutism in females
- androgen receptor blockade in transgender therapy
- acne vulgaris
Contraindications:
- Hyperkalaemia
- Hyponatraemia
- Anuria
- Addison’s disease
- Acute porphyrias
- Pregnancy
Precautions:
Potential metabolic products carcinogenic in rodents
Elderly
Adverse reactions:
gyno
electrolyte imbalances
Interactions:
abiraterone may be opposed by spironolactone
Dosing/Current guidelines:
Oedema and ascites in cirrhosis of the liver
100–400 mg daily, adjusted according to response
Malignant ascites
initially 100–200 mg daily, increased to 400 mg daily if required
Nephrotic syndrome
100–200 mg daily
Oedema in heart failure
initially 100 mg (range 25–200 mg) daily in single or divided doses; maintenance dose adjusted according to response
Moderate to severe heart failure (adjunct)
initially 25 mg once daily, increased according to response to maximum 50 mg once daily
Resistant hypertension (adjunct)
25 mg once daily
Primary hyperaldosteronism
in patients awaiting surgery, 100–400 mg daily; long-term maintenance if surgery inappropriate, use lowest effective dose
Female hirsutism
50–200 mg in divided doses
Overdose:
may manifest as nausea vomiting dizziness and drowsiness, mental confusion, rash or diaorrheoa
Treatment of OD:
treat fluid depletion, electrolyte imbalances and hypotension should be treated
hyperkalaemia can be treated with glucose and insulin
Pregnancy:
animal studies suggest risk
Subsidised:
Tablet (Spiractin) and oral liquid are fully subsidised
Use in sport:
S5 (Diuretics and masking agents): prohibited at all times (in- and out-of-competition)
What to tell patients:
Comments/Observations/notes: