Indication
Frusemide & Spironolactone combination is indicated in-
Essential hypertension
Chronic congestive heart failure
Hepatic cirrhosis, with collection of fluid in the abdominal cavity (ascites)
Swelling due to excess fluid retention (edema)
Hyperaldosteronism
Resistant edema associated with secondary hyperaldosteronism
Pharmacology
Spironolactone (potassium sparing diuretic) and Furosemide (loop diuretic) have different but complementary mechanisms and sites of action. Therefore, when given together they produce additive or synergistic diuretic. The Furosemide component inhibits the Na+/K+/2Cl- co-transporter in the ascending Loop of Henle and blocks the reabsorption of sodium, potassium and chloride ions; thereby increasing the quantity of sodium and the volume of water excreted in the urine. This characteristically induces potassium loss. The spironolactone component inhibits the reabsorption of sodium in exchange for potassium at the distal tubule by antagonising the action of aldosterone so that sodium excretion is greatly favoured and the excess loss of potassium, induced by the Furosemide, is reduced
Dosage
Furosemide 20 and spironolactone 50 mg: 1 to 4 tablets daily (20 to 80 mg of Furosemide and 50 to 200 mg of spironolactone) according to the patient??s response.Furosemide 40 and spironolactone 50 mg: For previously stabilized patients requiring higher dosage of spironolactone and Furosemide, This tablet can be used at a dose of one to two tablets daily (Furosemide 40 to 80 mg and spironolactone 50 to 100 mg).
Interaction
When taken together with ACE inhibitors or potassium salts there is an increased risk of hyperkalemia. Spironolactone increases the levels of cardiac glycosides such as digoxin in the blood and this may result in digitalis toxicity. Corticosteroids may cause hypokalemia if they are used with Spironolactone. The blood pressure lowering and diuretic effects of Furosemide may be reduced or abolished when used together with indomethacin and possibly other non-steroidal anti-inflammatory drugs (NSAIDs). Furosemide may increase the ototoxicity of aminoglycoside antibiotics. Simultaneous administration of sucralfate and Furosemide may reduce the natriuretic and anti-hypertensive effect of Furosemide.
Contradiction
Contraindicated in patients with anuria, acute renal insufficiency, rapidly deteriorating or severe impairment of renal function (creatinine clearance <30 ml/min), hyperkalaemia, Addison's disease and in patients who are hypersensitive to Spironolactone, Furosemide or sulphonamides.
Side Effect
Spironolactone may give rise to headache and drowsiness and gastrointestinal distress, including cramp and diarrhoea. Ataxia, mental confusion, and skin rashes have been reported as side effect. Gynaecomastia is not uncommon and in rare cases breast enlargement may persist. Other endocrine disorders including hirsutism, deepening of the voice, menstrual irregularities and impotence. Transient increase in blood-urea-nitrogen concentrations may occur and mild acidosis has been reported. Spironolactone may cause hyponatremia and hyperkalemia. Excessive diuresis may result in dehydration and reduction in blood volume with circulatory collapse with the possibility of vascular thrombosis and embolism particularly in elderly patients. Serious depletion of potassium and magnesium may lead to cardiac arrhythmias.
Pregnancy
Pregnancy: Spironolactone and its metabolites may cross the placental barrier. The use of spironolactone in pregnant women requires that the anticipated benefit be weighed against the possible hazards to the mother and fetus. Animal teratology studies indicate that Furosemide may cause fetal abnormalities. Therefore, Furosemide should only be used in women in child bearing age when appropriate contraceptive measures are taken or if the potential benefits justify the potential risks to the fetus.Lactation: Metabolites of Spironolactone have been detected in breast milk. If use of Spironolactone is considered essential, an alternative method of infant feeding should be instituted. Furosemide is excreted in breast milk and breast-feeding should be discontinued if treatment is essential.
Precaution
Caution should be taken in patients liable to electrolyte deficiency. This preparation should also be used with caution in diabetes, enlarged prostate, hypotension and in hypovolemia.
Overdose
Symptoms of overdosage include drowsiness, mental confusion, dizziness, diarrhea and vomiting etc. due to excessive diuresis. Treatment should be aimed at the replacement of fluid and correction of any electrolyte imbalance.
Storage
Keep below 30?øC temperature, away from light & moisture. Keep out of the reach of children.