Usage
Amiloride + Torasemide is prescribed for the treatment of edema (fluid overload) associated with heart failure, hepatic cirrhosis (chronic liver damage), and renal disease. It is classified as a combination diuretic. Its mechanism of action involves increasing urine excretion by the kidneys, reducing excess fluid in the body. This, in turn, reduces the workload on the heart and improves its efficiency in pumping blood, thus also helping lower high blood pressure.
Alternate Names
No widely recognized alternate names exist for the combination product itself. However, the individual components are known as:
- Amiloride: Midamor (brand name)
- Torasemide: Demadex, Soaanz (brand names)
How It Works
Pharmacodynamics: Amiloride is a potassium-sparing diuretic that blocks the epithelial sodium channel (ENaC) in the distal convoluted tubule of the nephron. This inhibits sodium reabsorption and potassium secretion. Torasemide is a loop diuretic that inhibits the Na+-K+-2Cl- cotransporter in the thick ascending limb of the loop of Henle, also increasing sodium, chloride, and water excretion. The combination results in enhanced diuresis while mitigating potassium loss.
Pharmacokinetics:
- Absorption: Both drugs are orally absorbed.
- Metabolism: Torasemide is partially metabolized in the liver, while amiloride undergoes minimal hepatic metabolism.
- Elimination: Amiloride is primarily excreted unchanged in the urine, whereas torasemide is eliminated via both renal and hepatic routes.
Mode of Action: As described above, this combination acts on distinct parts of the nephron to achieve diuresis and potassium sparing effects.
Receptor Binding, Enzyme Inhibition, or Neurotransmitter Modulation: Amiloride binds to and blocks ENaC channels. Torasemide inhibits the Na+-K+-2Cl- cotransporter. No neurotransmitter modulation is involved.
Elimination Pathways: Amiloride primarily undergoes renal excretion. Torasemide undergoes both renal and hepatic excretion.
Dosage
Standard Dosage
Adults:
- Edema (Heart Failure): Initial dose: Torasemide 10-20 mg orally once daily. May increase up to 200 mg/day. Amiloride 5 mg once daily, adjustable up to 20 mg/day based on potassium levels.
- Edema (Renal Failure): Initial dose: Torasemide 20 mg orally once daily, adjustable up to 200 mg/day. Amiloride 5 mg once daily, adjustable based on potassium levels.
- Edema (Hepatic Cirrhosis): Initial dose: Torasemide 5-10 mg orally once daily combined with an aldosterone antagonist or potassium-sparing diuretic, adjustable up to 40 mg/day. Amiloride 5 mg once daily, adjustable based on potassium levels.
- Hypertension: Initial dose: Torasemide 2.5 mg orally once daily, may increase to 5 mg and then 10 mg if needed. Amiloride 5 mg once daily, adjustable based on potassium levels.
Children:
Not recommended for children under 12 years of age. Dosing must be determined by a doctor on a case-by-case basis for older children.
Special Cases:
- Elderly Patients: Start with lower doses and titrate carefully due to increased risk of side effects.
- Patients with Renal Impairment: Dose adjustments may be necessary for torsemide. Amiloride is not recommended for patients with severe renal impairment.
- Patients with Hepatic Dysfunction: Close monitoring is required due to potential alterations in drug metabolism. Dose adjustments may be needed for torsemide.
- Patients with Comorbid Conditions: For example, patients with diabetes should be monitored for changes in blood glucose levels. Patients with gout should be aware of the potential for exacerbation.
Clinical Use Cases
The provided sources do not include specific dosing recommendations for clinical use cases such as Intubation, Surgical Procedures, Mechanical Ventilation, ICU Use, or Emergency Situations. Dosage needs to be individualized based on patient factors, and clinical context.
Dosage Adjustments
Dose adjustments are based on patient-specific factors like renal function, hepatic function, and electrolyte levels, as well as the clinical response. Close monitoring of serum electrolytes, especially potassium, is necessary.
Side Effects
Common Side Effects:
Headache, dizziness, nausea, dehydration, electrolyte imbalances (especially hypokalemia), increased uric acid levels, muscle cramps, and weakness.
Rare but Serious Side Effects:
Severe hypotension, cardiac arrhythmias (including ventricular fibrillation), and allergic reactions.
Long-Term Effects:
Electrolyte imbalances, gout, and hyperglycemia.
Adverse Drug Reactions (ADR):
Hypersensitivity reactions, Stevens-Johnson Syndrome, toxic epidermal necrolysis.
Contraindications
Anuria, severe renal or hepatic impairment, hyperkalemia, concomitant use of potassium supplements or other potassium-sparing diuretics (unless closely monitored), hypersensitivity to either amiloride or torsemide, and pregnancy.
Drug Interactions
ACE inhibitors, angiotensin receptor blockers (ARBs), NSAIDs, digoxin, lithium, aminoglycosides, corticosteroids, and other diuretics. Concomitant use of potassium supplements or potassium-rich foods should be avoided. Alcohol may enhance the hypotensive effects.
Pregnancy and Breastfeeding
Use is contraindicated in pregnancy and breastfeeding. Torsemide is a pregnancy category B drug but still not recommended. Amiloride’s effects during pregnancy are not well-studied. Both drugs can potentially enter breast milk.
Drug Profile Summary
- Mechanism of Action: Combination diuretic acting on distal convoluted tubule (amiloride) and loop of Henle (torasemide).
- Side Effects: Dehydration, electrolyte imbalance, headache, dizziness, nausea.
- Contraindications: Anuria, severe renal/hepatic impairment, hyperkalemia, pregnancy.
- Drug Interactions: Numerous; see detailed section above.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: See detailed section above.
- Monitoring Parameters: Serum electrolytes (potassium, sodium, magnesium, calcium), renal function, blood pressure, and blood glucose.
Popular Combinations
Often used with other antihypertensives such as ACE inhibitors or ARBs when monotherapy is insufficient. However, careful monitoring of potassium levels is essential.
Precautions
Monitor electrolyte levels, renal function, and blood pressure. Caution in patients with diabetes, gout, or cardiovascular disease. Avoid in pregnancy and breastfeeding. Advise patients to take the medication during the day to prevent nocturia.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Amiloride + Torasemide?
A: Dosing is individualized based on the indication and patient-specific factors. Refer to the Dosage section above for detailed guidelines.
Q2: How should Amiloride + Torasemide be administered?
A: Orally, once daily, preferably in the morning to avoid nighttime urination.
Q3: What are the major drug interactions with Amiloride + Torasemide?
A: Significant interactions exist with ACE inhibitors, ARBs, NSAIDs, digoxin, lithium, aminoglycosides, and other diuretics. See detailed section above.
Q4: Can Amiloride + Torasemide be used in patients with renal impairment?
A: Torasemide requires dosage adjustments in renal impairment. Amiloride is not recommended in severe renal failure.
Q5: Is Amiloride + Torasemide safe during pregnancy and breastfeeding?
A: No, it is contraindicated.
Q6: What are the common side effects of Amiloride + Torasemide?
A: Headache, dizziness, nausea, dehydration, and electrolyte imbalances.
Q7: What should be monitored in patients taking Amiloride + Torasemide?
A: Serum electrolytes, blood pressure, renal function, and blood glucose (in diabetics).
Q8: What are the contraindications for Amiloride + Torasemide?
A: Anuria, severe renal/hepatic dysfunction, hyperkalemia, and hypersensitivity.
Q9: Can patients take potassium supplements while on Amiloride + Torasemide?
A: Generally no, due to the risk of hyperkalemia. Potassium intake should be discussed with the physician.
Q10: What is the role of Amiloride in the combination?
A: Amiloride is a potassium-sparing diuretic that helps prevent excessive potassium loss caused by torasemide, a “potassium-wasting” diuretic.
