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. Adverse effects due to
torasemide are usually mild and transient in nature. No evidence of
ototoxicity has been demonstrated in humans, and
torasemide does not appear to affect
blood glucose levels, serum
uric acid concentrations, or serum
potassium levels at dosages below 5 mg/day. Thus, additional evidence has accumulated for the clinical efficacy of
torasemide in the management of mild to moderate
essential hypertension and oedematous conditions which require
diuretic therapy. Further studies are now required to confirm the long term efficacy and tolerability of
torasemide, and to investigate the place of the
drug in
therapy relative to
cardiovascular agents other than
furosemide and the
thiazide diuretics.