Usage
Indapamide + Telmisartan is prescribed for the treatment of essential hypertension (high blood pressure) in patients whose blood pressure is not adequately controlled on telmisartan alone. It combines a thiazide-like diuretic (indapamide) with an angiotensin II receptor blocker (ARB) (telmisartan). These agents belong to the antihypertensive classification.
The combination targets two different mechanisms related to blood pressure regulation. Telmisartan blocks the angiotensin II receptor, preventing vasoconstriction. Indapamide increases the excretion of sodium and water by the kidneys, reducing blood volume and further lowering blood pressure.
Alternate Names
No widely recognized alternate generic names exist. However, it is sometimes referred to as the combination of its components, telmisartan/indapamide. Brand names include Telma-D.
How It Works
Pharmacodynamics: Telmisartan blocks the angiotensin II type 1 (AT1) receptor, inhibiting the vasoconstrictor and aldosterone-secreting effects of angiotensin II. Indapamide inhibits sodium reabsorption in the distal convoluted tubule of the nephron, leading to increased sodium and water excretion and reduced blood volume.
Pharmacokinetics:
- Telmisartan: Orally administered telmisartan is well absorbed, with peak plasma concentration reached in 0.5-1.5 hours. It undergoes minimal metabolism and primarily excreted in the feces via biliary excretion.
- Indapamide: Orally administered indapamide is rapidly absorbed with a high degree of bioavailability (over 90%). Peak plasma levels are reached within 1–2 hours. It undergoes hepatic metabolism and primarily excreted in urine (70%) with 23% excreted in the feces.
Mode of Action: Telmisartan exerts its antihypertensive effect by blocking AT1 receptors, leading to vasodilation and reduced aldosterone secretion. Indapamide exerts its antihypertensive effect by inhibiting sodium reabsorption in the distal convoluted tubule, leading to increased excretion of sodium and water, which reduces blood volume.
Elimination Pathways: Telmisartan is primarily eliminated by biliary/fecal excretion. Indapamide is primarily eliminated renally with some fecal excretion.
Dosage
Standard Dosage
Adults:
The standard dose is one tablet of Indapamide 1.5mg/Telmisartan 40mg once daily. The dosage may be increased based on the patient’s blood pressure response to one tablet containing 1.5 mg indapamide and 80 mg telmisartan or, when clinically appropriate, by individual titration of the two components.
Children:
Safety and efficacy have not been established in children below the age of 18 years.
Special Cases:
- Elderly Patients: Initial dose should consider blood pressure response and renal function.
- Patients with Renal Impairment: Contraindicated in severe renal impairment (creatinine clearance < 30 mL/min). In moderate renal impairment (creatinine clearance 30-60 mL/min), start with a lower dose.
- Patients with Hepatic Dysfunction: Contraindicated in severe hepatic impairment. Monitor carefully in mild to moderate hepatic impairment.
- Patients with Comorbid Conditions: Adjust dosage as needed based on other medications and conditions. For patients with diabetes, monitor blood sugar levels closely.
Clinical Use Cases
Indapamide + Telmisartan is specifically indicated for essential hypertension and is not typically used in acute clinical settings like intubation, surgical procedures, mechanical ventilation, ICU, or emergency situations. Other antihypertensive medications with more rapid onset of action might be more appropriate in those contexts.
Dosage Adjustments
Dosage adjustment may be necessary based on patient-specific factors such as renal/hepatic dysfunction, other medications, and individual blood pressure response.
Side Effects
Common Side Effects
Dizziness, headache, fatigue, upper respiratory tract infections, back pain, cough, nausea, diarrhea, and orthostatic hypotension.
Rare but Serious Side Effects
Angioedema, acute renal failure, hypotension, syncope, hyperkalemia, hyponatremia, and hepatotoxicity.
Long-Term Effects
Electrolyte imbalances, renal impairment, and cardiovascular events if blood pressure remains uncontrolled.
Adverse Drug Reactions (ADR)
Angioedema, severe hypotension, and anaphylaxis (rare).
Contraindications
Hypersensitivity to telmisartan, indapamide, or other sulfonamides; pregnancy; bilateral renal artery stenosis; severe renal impairment; severe hepatic impairment; anuria; concomitant use of aliskiren in patients with diabetes.
Drug Interactions
- Nonsteroidal anti-inflammatory drugs (NSAIDs): May reduce antihypertensive effect.
- Lithium: Increased lithium toxicity possible.
- Other antihypertensives: Additive effects, may require dose adjustment.
- Potassium-sparing diuretics: Increased risk of hyperkalemia.
- Digoxin: May increase digoxin levels.
Pregnancy and Breastfeeding
Contraindicated in pregnancy and breastfeeding due to potential fetal and neonatal harm.
Drug Profile Summary
- Mechanism of Action: Angiotensin II receptor blockade and thiazide-like diuresis.
- Side Effects: Dizziness, headache, fatigue, orthostatic hypotension, angioedema (rare).
- Contraindications: Pregnancy, bilateral renal artery stenosis, severe renal/hepatic impairment, hypersensitivity.
- Drug Interactions: NSAIDs, lithium, other antihypertensives.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: 1.5mg/40mg once daily; adjust based on response.
- Monitoring Parameters: Blood pressure, renal function (creatinine, potassium), electrolytes (sodium, potassium).
Popular Combinations
This drug itself is a combination product; further combinations should be based on the individual patient’s needs and under careful medical supervision.
Precautions
Monitor blood pressure, renal function, and electrolytes. Caution in patients with renal or hepatic impairment, diabetes, or gout. May cause dizziness or orthostatic hypotension; advise patients to avoid driving or operating machinery until effects are known.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Indapamide + Telmisartan?
A: The standard starting dose is one tablet of Indapamide 1.5mg/Telmisartan 40mg once daily.
Q2: How does Indapamide + Telmisartan differ from monotherapy with either drug alone?
A: The combination provides enhanced blood pressure reduction compared to either drug alone by targeting two distinct mechanisms of blood pressure regulation.
Q3: Can Indapamide + Telmisartan be used in patients with diabetes?
A: It can be used with caution and close monitoring of blood glucose levels.
Q4: What are the key drug interactions to be aware of?
A: NSAIDs, lithium, other antihypertensives, and potassium-sparing diuretics.
Q5: What are the most common side effects?
A: Dizziness, headache, fatigue, and orthostatic hypotension.
Q6: Is Indapamide + Telmisartan safe during pregnancy?
A: No, it is contraindicated during pregnancy and breastfeeding.
Q7: How should I adjust the dosage in patients with renal impairment?
A: Contraindicated in severe renal impairment. Lower dose should be used for moderate impairment and creatinine, potassium should be monitored closely.
Q8: How does this combination reduce cardiovascular risk?
A: By lowering blood pressure, the combination helps to reduce the strain on the heart and blood vessels, consequently lowering the risk of cardiovascular events like stroke and heart attack.
Q9: When should I expect to see a noticeable improvement in blood pressure?
A: The antihypertensive effect of telmisartan is usually apparent within 2 weeks, with the maximum reduction generally attained after 4 weeks. Indapamide’s effect is usually seen within a few days.
