Raw material Telmisartan

Telmisartan More Info

Telmisartan is an orally active, specific angiotensin II receptor (type AT₁) antagonist. It belongs to the class of drugs known as angiotensin II receptor blockers (ARBs) or "sartans". It was developed by Boehringer Ingelheim (Germany) and is also marketed under brand names such as Micardis and Pritor.

Mechanism of Action

Telmisartan works by selectively blocking the AT₁ receptor, blocking the vasoconstrictor and aldosterone-secreting effects of angiotensin II. It displaces angiotensin II with very high affinity from its binding site at the AT₁ receptor subtype . Telmisartan does not exhibit any partial agonist activity at the AT₁ receptor and has essentially no affinity for the AT₂ receptor. Plasma aldosterone levels are decreased by telmisartan.

It is important to note that, unlike ACE inhibitors, telmisartan does not cause angioedema or cough, as it does not affect bradykinin or substance P.

Additionally, telmisartan acts as a selective modulator of peroxisome proliferator-activated receptor gamma (PPAR-γ), which is a regulator of insulin and glucose metabolism. This dual action helps protect against vascular and renal damage caused by diabetes and cardiovascular disease.

Chemical Properties

Chemical Formula: C₃₃H₃₀N₄O₂

Molecular Weight: 514.62

CAS Number: 144701-48-4

Chemical Name: 4′-[(1,4′-dimethyl-2′-propyl[2,6′-bi-1H-benzimidazol]-1′-yl)methyl]-[1,1′-biphenyl]-2-carboxylic acid

Pharmacokinetics

Telmisartan is rapidly absorbed with an oral bioavailability of about 42% at 40 mg and about 58% at 160 mg. Peak plasma concentration is reached 0.5–1 hour after oral administration. It is highly protein-bound (to albumin and α1-acid glycoprotein), has a large volume of distribution of approximately 500 L, and is primarily excreted in the feces. The terminal elimination half-life is approximately 24 hours .

Indications

Telmisartan is indicated for the treatment of essential hypertension, and may be used alone or in combination with other antihypertensive agents. It can also be used in combination therapy, such as with hydrochlorothiazide or amlodipine.

Dosage Forms and Administration

Telmisartan is available as 20 mg, 40 mg, and 80 mg tablets for oral administration. The usual starting dose for adults is 40 mg once daily, and the dose may be increased to 80 mg if needed. Fixed-dose combinations include telmisartan + hydrochlorothiazide (40/12.5, 80/12.5, 80/25) and telmisartan + amlodipine (40/5, 40/10, 80/5, 80/10).