Inospiron 100 Tablet

What is Inospiron?

Inospiron is a brand of Spironolactone manufactured by Incepta Pharmaceuticals Ltd. It is a potassium-sparing diuretic and aldosterone antagonist used in the management of edema, ascites, congestive heart failure, and primary hyperaldosteronism.

Indications

Inospiron is indicated for the management of edema and ascites in cirrhosis of the liver, malignant ascites, nephrotic syndrome, congestive heart failure and primary hyperaldosteronism.

Pharmacology

Spironolactone is an antagonist of aldosterone and a potassium-sparing diuretic. It acts primarily through competitive binding of receptors at the aldosterone-dependent sodium-potassium exchange site in the distal convoluted renal tubule, causing increased excretion of sodium and water while retaining potassium and magnesium. The mean time to peak plasma concentration is 2.6 hours for spironolactone and 4.3 hours for its active metabolite canrenone. The mean half-life of spironolactone is 1.4 hours, while its active metabolites have half-lives of 13.8-16.5 hours.

Dosage & Administration

Heart Failure: Initiate at 25 mg once daily.
Hypertension: 25 to 100 mg daily in single or divided doses.
Edema (CHF, hepatic cirrhosis, nephrotic syndrome): 50-100 mg daily, ranging from 25 to 200 mg daily.
Hypokalemia: 25-100 mg daily.
Primary hyperaldosteronism: May be used as an initial diagnostic measure while on a normal diet.
Food increases bioavailability by approximately 95%, so a routine pattern with meals should be established.

Interaction

Potassium supplements, a potassium-rich diet, salt substitutes, or other potassium-sparing agents are not recommended due to risk of hyperkalemia. Severe hyperkalemia has been reported with concurrent ACE inhibitors. Aspirin attenuates the diuretic effect by blocking canrenone secretion in the renal tubule. Indomethacin and mefenamic acid inhibit canrenone excretion. Concurrent use with carbenoxolone should be avoided. Spironolactone reduces vascular responsiveness to noradrenaline and enhances the metabolism of antipyrine.

Contraindications

Acute renal insufficiency, significant impairment of renal function, anuria, hyperkalemia, or hypersensitivity to spironolactone.

Side Effects

Gynaecomastia (dose- and duration-related, usually reversible), gastrointestinal symptoms including cramping and diarrhoea, drowsiness, lethargy, headache, maculopapular or erythematous skin eruptions, urticaria, mental confusion, drug fever, ataxia, impotence, irregular menses or amenorrhoea, and post-menopausal bleeding.

Pregnancy & Lactation

There are risks to mother and fetus from poorly controlled heart failure, cirrhosis, or hypertension during pregnancy. No data exist on effects on milk production; use with caution during lactation.

Precautions & Warnings

Monitor for fluid and electrolyte imbalance including hypomagnesemia, hyponatremia, hypochloremic alkalosis, and hyperkalemia, especially during excessive vomiting or parenteral fluid therapy. Hyperkalemia is more likely in renal impairment or excessive potassium intake and can cause fatal cardiac irregularities; potassium supplementation should ordinarily be avoided.

Therapeutic Class

Potassium-sparing diuretics and aldosterone antagonists.

Storage Conditions

Keep out of reach of children. Store in a dry place, below 30°C, protected from light.