DIURIDE INJECTION

Indications

• Hypertension
• Congestive heart failure
• Edema associated with renal disease
• Acute renal failure

Dosage

Adults: The typical adult

Mechanism of action

Torsemide acts by inhibiting the Na+/K+/Cl- cotransporter in the luminal cell membrane of the medullary thick ascending loop of Henle. This inhibition occurs through binding to a chloride ion-binding site on the transport molecule, reducing sodium, potassium, and chloride reabsorption. Additionally, torsemide affects the renin-angiotensin-aldosterone system by inhibiting the downstream effects of angiotensin II, leading to decreased aldosterone synthesis and receptor activity.

Pharmacodynamics

Torsemide increases urine output, facilitating fluid and electrolyte balance while reducing the risk of renal injury and acute renal failure. It exhibits a long-lasting diuretic effect with less potassium excretion compared to other diuretics, attributed to its influence on the renin-angiotensin-aldosterone system. Torsemide has been reported to lower plasma brain natriuretic peptide levels and improve left ventricular function in patients with heart failure, as well as reduce blood pressure and extracellular fluid volume in hypertensive patients, especially those with chronic kidney disease.

Pharmacokinetics

Torsemide is well absorbed from the gastrointestinal tract, with peak plasma concentrations typically occurring within 1 to 2 hours after oral administration. It is extensively bound to plasma proteins, primarily albumin. The drug undergoes hepatic metabolism, primarily by cytochrome P450 enzymes, with a half-life of approximately 3 to 4 hours. Renal excretion of torsemide and its metabolites is significant, with approximately 80% of the dose eliminated through urine. The pharmacokinetics may be altered in patients with renal impairment.

Adverse effects

• Hypokalemia
• Dehydration
• Electrolyte imbalance
• Hypotension
• Renal impairment
• Gastrointestinal disturbances
• Rash

Interactions

• Aminoglycosides
• Antidiabetic agents
• Antihypertensive drugs
• NSAIDs
• Lithium

Precautions

• Monitor renal function regularly
• Electrolyte levels should be monitored
• Use cautiously in patients with a history of gout
• Caution in patients with diabetes mellitus

Pregnancy

Use in pregnancy only if the potential benefit justifies the potential risk to the fetus. Limited human data available.

Breast-feeding

Use with caution, as it is not known if torsemide is excreted in human milk.

Storage

Store at room temperature, away from moisture and direct light.

Formulations

• Tablets: 5 mg, 10 mg, 20 mg
• Injection: 10 mg/2 ml

Mechanism of action

As mentioned above, torasemide is part of the loop diuretics and thus, it acts by reducing the oxygen demand in the medullary thick ascending loop of Henle by inhibiting the Na+/K+/Cl- pump on the luminal cell membrane surface. This action is obtained by the binding of torasemide to a chloride ion-binding site of the transport molecule. Torasemide is known to have an effect in the renin-angiotensin-aldosterone system by inhibiting the downstream cascade after the activation of angiotensin II. This inhibition will produce a secondary effect marked by the reduction of the expression of aldosterone synthase, TGF-B1 and thromboxane A2 and a reduction on the aldosterone receptor binding.

Pharmacodynamics

It is widely known that administration of torasemide can attenuate renal injury and reduce the severity of acute renal failure. This effect is obtained by increasing urine output and hence, facilitating fluid, acid-base and potassium control. This effect is obtained by the increase in the excretion of urinary sodium and chloride. Several reports have indicated that torasemide presents a long-lasting diuresis and less potassium excretion which can be explained by the effect that torasemide has on the renin-angiotensin-aldosterone system. This effect is very similar to the effect observed with the administration of combination therapy with [furosemide] and [spironolactone] and it is characterized by a decrease in plasma brain natriuretic peptide and improved measurements of left ventricular function. Above the aforementioned effect, torasemide presents a dual effect .in which the inhibition of aldosterone which donates torasemide with a potassium-sparing action. Torasemide has been shown to reduce extracellular fluid volume and blood pressure in hypertensive patients suffering from chronic kidney disease. As well, some reports have indicated that torasemide can reduce myocardial fibrosis by reducing the collagen accumulation. This effect is suggested to be related to the decrease in aldosterone which in order has been shown to reduce the production of the enzyme procollagen type I carboxy-terminal proteinase which is known to be overexpressed in heart failure patients.