1. Clinical Overview
A fixed-dose combination (FDC) of an Angiotensin II Receptor Blocker (ARB) and an Angiotensin-Converting Enzyme (ACE) inhibitor. This dual renin-angiotensin-aldosterone system (RAAS) blockade provides synergistic antihypertensive and cardioprotective effects, offering superior blood pressure control and potential organ protection compared to monotherapy, particularly in high-risk hypertensive patients with diabetes or chronic kidney disease.
| Onset | Duration | Bioavailability |
|---|---|---|
| Telmisartan: 1-2 hours; Ramipril: 1-2 hours (peak plasma concentration). Significant antihypertensive effect observed within 2-4 hours. | Telmisartan: >24 hours; Ramipril: 24 hours. The combination provides sustained 24-hour blood pressure control with once-daily dosing. | Telmisartan: 42-58%; Ramipril: 28-30% (Ramiprilat, the active metabolite: 45-50%). |
2. Mechanism of Action
Provides dual blockade of the Renin-Angiotensin-Aldosterone System (RAAS). Ramipril inhibits the Angiotensin Converting Enzyme (ACE), reducing the conversion of Angiotensin I to the potent vasoconstrictor Angiotensin II and decreasing the breakdown of bradykinin (a vasodilator). Telmisartan selectively and competitively blocks the binding of Angiotensin II to the AT1 receptor subtype, which mediates vasoconstriction, aldosterone secretion, and sympathetic activation. This dual action results in more complete RAAS suppression, leading to vasodilation, reduced aldosterone secretion (decreasing sodium/water retention), and decreased cardiac afterload and preload.
3. Indications & Uses
- Essential Hypertension (Severe or Resistant)
- Hypertension with Type 2 Diabetes Mellitus with nephropathy (proteinuria)
4. Dosage & Administration
Adult Dosage: One tablet (Telmisartan 40mg + Ramipril 5mg) once daily. Initiation with this FDC is not recommended. Therapy should be initiated after individual titration of each component. Dose may be increased to Telmisartan 80mg + Ramipril 10mg (as separate tablets or higher strength FDC if available) if needed and tolerated.
Administration: Can be taken with or without food, but consistency is advised. Preferably taken at the same time each day, often in the morning to control daytime BP. If taken once daily and BP is not controlled over 24 hours, consider evening dosing or divided doses (as separate components). Ensure adequate hydration. Do not crush or chew.
5. Side Effects
Common side effects may include:
- Dizziness
- Headache
- Fatigue
- Persistent dry cough (more related to Ramipril)
- Hypotension (especially initial doses)
- Hyperkalemia (mild)
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Diuretics (especially Potassium-Sparing: Spironolactone, Amiloride) | Profound first-dose hypotension; Severe hyperkalemia | Major |
| NSAIDs (e.g., Ibuprofen, Diclofenac) | Reduced antihypertensive effect; Risk of acute renal failure; Increased hyperkalemia | Major |
| Lithium | Increased serum lithium levels and toxicity | Major |
| Aliskiren | Increased risk of hyperkalemia, hypotension, and renal impairment (contraindicated in diabetes/CKD) | Major |
| Potassium Supplements/Salt Substitutes | Increased risk of hyperkalemia | Major |
| Other Antihypertensives (Beta-blockers, CCBs) | Additive hypotensive effect | Moderate |
| Antidiabetics (Insulin, Sulfonylureas) | Enhanced hypoglycemic effect | Moderate |
| Gold Injections (Sodium aurothiomalate) | Increased risk of nitritoid reactions (flushing, hypotension) with Ramipril | Moderate |
7. Patient Counselling
- DO take the medicine at the same time every day.
- DO inform all doctors and surgeons (including dentists) that you are taking this medicine.
- DO get regular blood tests for kidney function and potassium as advised.
- DO maintain adequate fluid intake unless advised otherwise.
- DONT stop taking the medicine suddenly; consult your doctor.
- DONT take over-the-counter painkillers (NSAIDs like Ibuprofen) without consulting your doctor.
- DONT use potassium supplements or salt substitutes without medical advice.
8. Toxicology & Storage
Overdose: Profound hypotension, tachycardia or bradycardia, circulatory shock, hyperkalemia, acute renal failure, dizziness, syncope.
Storage: Store below 30°C. Protect from light and moisture. Keep in the original blister pack or container. Keep out of reach of children. Do not use after the expiry date printed on the pack.