TORASEMIDE - AN UPDATE OF ITS PHARMACOLOGICAL PROPERTIES AND THERAPEUTIC EFFICACY

The pharmacological properties and therapeutic use of the high-ceiling loop diuretic torasemide (torsemide) were previously reviewed in Drugs in 1991, the following being a re-examination of the role of the drug in the light of data that have subsequently become available (particularly in the management of oedematous disorders). Torasemide produces a more prolonged water and electrolyte excretion than equipotent diuretic doses of furosemide (frusemide), but does not increase kaliuresis to the same extent. Dosages of torasemide of 2.5 to 5 mg/day do not affect plasma renin activity or aldosterone release to a clinically significant extent, although torasemide 20mg increases plasma renin levels, angiotensin II activity and urinary dopamine and prostaglandin E excretion. Studies published since the previous review have confirmed the efficacy of low dosages of torasemide (2.5 to 5 mg/day) in the treatment of hypertension, and have shown it to be effective when administered orally at a dosage of 5 to 20 mg/day in the management of congestive heart failure. Dosages of up to 400 mg/day increased urinary volume excretion and natriuresis in patients with chronic renal failure. Bodyweight and peripheral oedema were reduced by torasemide 10 to 200 mg/day as monotherapy, and 5 to 20 mg/day when coadministered with spironolactone, in patients with nephrotic syndrome. Dosages of 10 to 40 mg/day, either as monotherapy or in conjunction with an aldosterone antagonist, reduced ascites, oedema and bodyweight in patients with hydropically decompensated liver failure.