Telmisartan Tablets

Mechanism

Telmisartan selectively blocks the binding of angiotensin II to the AT1 receptor in vascular smooth muscle. This prevents vasoconstriction and aldosterone secretion, leading to vasodilation, reduced blood pressure, and decreased sodium and water retention.

Pharmacokinetics

• Absorption: Rapidly absorbed after oral administration; bioavailability ~40–60%. Food slightly reduces absorption but not clinically significant.
• Distribution: Highly bound to plasma proteins (>99.5%), mainly albumin. Large volume of distribution (~500 L), indicating extensive tissue penetration.
• Metabolism: Minimal hepatic metabolism; mainly conjugated to glucuronide. No significant CYP450 involvement, reducing drug–drug interaction risk.
• Elimination: Excreted primarily unchanged in feces via biliary route; negligible renal clearance.
• Half-life:Long elimination half‑life (~24 hours), supporting once‑daily dosing.

Side Effects

• Dizziness
• Hypotension
• Hyperkalemia
• Fatigue
• Back pain

Contraindication

• Hypersensitivity to telmisartan
• Pregnancy (especially second and third trimester)
• Severe hepatic impairment
• Use with aliskiren in diabetic patients

Interaction

• Potassium supplements or potassium-sparing diuretics (risk of hyperkalemia)
• NSAIDs (may reduce antihypertensive effect)
• Lithium (increased lithium toxicity)
• ACE inhibitors or other ARBs (increased risk of adverse effects)

Warning and Precautions

• Avoid use during pregnancy due to risk of fetal toxicity
• Monitor kidney function and potassium levels
• Use cautiously in patients with renal artery stenosis
• May cause excessive drop in blood pressure in volume-depleted patients

Dosage

As directed by the Physician.