Spironolactone
Spironolactone is a potassium-sparing diuretic (water pill) that prevents your body from absorbing too much salt and keeps your potassium levels from getting too low. Spironolactone is used to diagnose or treat a condition in which you have too much aldosterone in your body.
Aldosterone is a hormone produced by your adrenal glands to help regulate the salt and water balance in your body. Spironolactone also treats fluid retention (edema) in people with congestive heart failure, cirrhosis of the liver, or a kidney disorder called nephrotic syndrome.
This medication is also used to treat or prevent hypokalemia (low potassium levels in the blood).
Mechanism of effect
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. Spironolactone causes increased amounts of sodium and water to be excreted, while potassium is retained.
Pharmacodynamic
Spironolactone is a synthetic 17-lactone steroid which is a renal competitive aldosterone antagonist in a class of pharmaceuticals called potassium-sparing diuretics
Pharmacokinetics
Fairly rapidly absorbed from the gastrointestinal tract. Food increases the bioavailability of unmetabolized spironolactone by almost 100%.
Spironolactone and its metabolites are more than 90% bound to plasma proteins. Rapidly and extensively metabolized. The metabolites are excreted primarily in the urine and secondarily in bile. Half life: 10 minutes.
Drug indications
(hypertension (high blood pressure , Congestive Heart Failure , Edema , Hypokalemia , (Primary Hyperaldosteronism Diagnosis(Conn's syndrome , Hirsutism , (Conn's syndrome)Primary HyperaldosteronismDosage
Usual Adult Dose for Edema
25 to 200 mg/day orally in 1 or 2 divided doses.
Usual Adult Dose for Hypertension
25 to 200 mg/day orally in 1 or 2 divided doses.
Usual Adult Dose for Hypokalemia
25 to 200 mg/day orally in 1 or 2 divided doses.
Usual Adult Dose for Primary Hyperaldosteronism Diagnosis
100 to 400 mg/day orally in 1 or 2 divided doses.
Usual Adult Dose for Hirsutism
50 to 200 mg/day orally in 1 or 2 divided doses.
Usual Adult Dose for Congestive Heart Failure
25 mg/day orally. Increase or decrease based on response and evidence of hyperkalemia.
Usual Pediatric Dose for Hypertension
Neonates: 1 to 3 mg/kg/day orally every 12 to 24 hours.
Children: 1.5 to 3.3 mg/kg/day or 60 mg/m2/day orally in divided doses every 6 to 12 hours not to exceed 100 mg/day.
Usual Pediatric Dose for Primary Hyperaldosteronism Diagnosis
Children: 100 to 400 mg/m2/day orally in 1 to 2 divided doses.
Drug contraindications
Severe Renal Impairment , Anuria, , hyperkalemia , Addison’s disease , with concomitant use of eplerenoneSide effects
nausea , Headache , dizziness , vomiting , Diarrhea , urticaria , thrombocytopenia , leukopenia , fever , confusion , Stevens-Johnson syndrome , Gynecomastia , gastritis , Hyperkalemia , ataxia , Anaphylactic reaction , renal failure , GI bleeding , amenorrhea , lethargy , breast pain , vasculitis , electrolyte disturbances , toxic epidermal necrolysisInteractions
Amlodipine/Atorvastatine , Anethum , Atracurium , Acetaminophen+caffein+acetylsalic , Expectorant codein , Infliximab , pentoxifylline , Tadalafil , Quinidine , Pethidine , Pancuronium , Levodopa/carbidopa , Nicorandil , Heparin , Vardenafil , Valsartan , Cholestyramine , Tranylcypromine , Drospirenone , Duloxetine , Rituximab , Ciprofloxacin , Cyclosporine , Enalapril , Tetracosactid , Triamterene-H , Mefenamic acid , Milrinone , Yohimbine , eplerenone , Amiloride , potassium citrate , ethacrynic acid , Trimethoprim , Bumetanide , Triamterene , Eprosartan , Perindopril , Canagliflozin , Telmisartan , Sacubitril and valsartan , Azilsartan , Candesartan , Irbesartan , Olmesartan , Betrixaban , Treprostinil , cosyntropin , xipamide , FidaxomicinAlerts
1-Unnecessary use of this drug should be avoided.
2-Excessive potassium intake may cause hyperkalemia in patients receiving Spironolactone. Potassium supplementation, either in the form of medication or as a diet rich in potassium, should not ordinarily be given in association with Spironolactone therapy
3-Hyperkalemia may be fatal. It is critical to monitor and manage serum potassium in patients with severe heart failure receiving Spironolactone.
4-Spironolactone should be used with caution in patients with impaired hepatic function because minor alterations of fluid and electrolyte balance may precipitate hepatic coma.
5-Lithium generally should not be given with diuretics
Points of recommendation
1-Patients who receive Spironolactone should be advised to avoid potassium supplements and foods containing high levels of potassium including salt substitutes.
2-Periodic determination of serum electrolytes to detect possible electrolyte imbalance should be done at appropriate intervals, particularly in the elderly and those with significant renal or hepatic impairments.
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