Irbesartan 150 mg Tablet (Irbevex 150): Each uncoated tablet contains: Irbesartan USP 150 mg.
Irbesartan 300 mg Tablet (Irbevex 300): Each uncoated tablet contains: Irbesartan USP 300 mg.
Irbesartan is an angiotensin II receptor (AT1 subtype) antagonist.
Irbesartan is a non-peptide compound, chemically described as a 2-butyl-3-[p-(o-1H-tetrazol-5-ylphenyl) benzyl]-1, 3-diazaspiro [4.4] non-1-en-4-one. Its molecular formula is C25H25N6O.
Irbesartan is a white to oﬀ-white, crystalline powder with a molecular weight of 428.5. It is a nonpolar compound with a partition coeﬃcient (octanol/water) of 10.1 at pH of 7.4. Irbesartan is slightly soluble in alcohol and methylene chloride and practically insoluble in water.
Pharmacological Classification: Angiotensin II receptor Blocker.
Pharmacology: Pharmacodynamics: Mechanism of action: Angiotensin II is the primary vasoactive hormone in the renin-angiotensin system. Its eﬀects include vasoconstriction and the stimulation of aldosterone secretion by the adrenal cortex.
Irbesartan blocks the vasoconstrictor and aldosterone-secreting eﬀects of angiotensin II by selectively blocking in a non competitive manner the binding of angiotensin II to the AT1 receptor found in many tissues. Irbesartan has no agonist activity at the AT1 receptor. AT2 receptors have been found in many tissues, but to date they have not been associated with cardiovascular homeostasis. Irbesartan has essentially no aﬃnity for the AT2 receptors.
Irbesartan does not inhibit angiotensin converting enzyme, also known as kininase II, the enzyme that converts angiotensin I to angiotensin II and degrades bradykinin, nor does it aﬀect renin or other hormone receptors or ion channels involved in cardiovascular regulation of blood pressure and sodium homeostasis.
Pharmacokinetics: Irbesartan is an orally active agent. The oral absorption of Irbesartan is rapid and complete with an average absolute bioavailability of 60% - 80%. Irbesartan exhibits linear pharmacokinetics over the therapeutic dose range with an average terminal elimination half-life of 11-15 hours.
Following oral administration, peak plasma concentrations are attained at 1.5-2 hours after Dosing. Steady-state concentrations are achieved within 3 days.
Irbesartan is approximately 96% protein-bound in the plasma, primarily to albumin and α1-acid glycoprotein.
The average volume of distribution of Irbesartan is 53-93 liters. Total plasma and renal clearances are in the range of 157 - 176 and 3.0 - 3.5 mL/minute, respectively.
Irbesartan is metabolized via glucuronide conjugation and oxidation by the cytochrome P-450 system. Following either oral or intravenous administration of 14C-labeled Irbesartan, more than 80% of the circulating plasma radioactivity is attributable to unchanged Irbesartan. The primary circulating metabolite is the inactive Irbesartan glucuronide (approximately 6%). The remaining oxidative metabolites do not add appreciably to the pharmacologic activity. Irbesartan and its metabolites are excreted by both biliary and renal routes. Following either oral or intravenous administration of 14C-labeled Irbesartan, about 20% of radioactivity is recovered in the urine and the remainder in the feces. Less than 2% of the dose is excreted in urine as unchanged Irbesartan.
IRBESARTAN is indicated in adults for the treatment of essential hypertension. It is also indicated for the treatment of renal disease in adult patients with hypertension and type 2 diabetes mellitus as part of an antihypertensive medicinal product regimen.
The usual recommended initial and maintenance dose is 150 mg once daily, with or without food. IRBESARTAN at a dose of 150 mg once daily generally provides a better 24 hour blood pressure control than 75 mg. However, initiation of therapy with 75 mg could be considered, particularly in haemodialysed patients and in the elderly over 75 years. In patients insufficiently controlled with 150 mg once daily, the dose of IRBESARTAN can be increased to 300 mg, or other antihypertensive agents can be added. In particular, the addition of a diuretic such as hydrochlorothiazide has been shown to have an additive effect with IRBESARTAN.
In hypertensive type 2 diabetic patients, therapy should be initiated at 150 mg Irbesartan once daily and titrated up to 300 mg once daily as the preferred maintenance dose for treatment of renal disease.
Hypersensitivity to the active substance or to any of the excipients. Second and third trimesters of pregnancy. Do not co-administer IRBESARTAN with aliskiren-containing medicines in patients with diabetes or with moderate to severe renal impairment (glomerular ﬁltration rate (GFR) <60 ml/min/l.73m2).
Intravascular volume depletion: symptomatic hypotension, especially after the ﬁrst dose, may occur in patients who are volume and/or sodium depleted by vigorous diuretic therapy, dietary salt restriction, diarrhoea or vomiting. Such conditions should be corrected before the administration of IRBESARTAN.
Renovascular hypertension: there is an increased risk of severe hypotension and renal insuﬃciency when patients with bilateral renal artery stenosis or stenosis of the artery to a single functioning kidney are treated with medicinal products that aﬀect the renin-angiotensin aldosterone system. While this is not documented with IRBESARTAN, a similar eﬀect should be anticipated with angiotensin-II receptor antagonists.
Renal impairment and kidney transplantation: when IRBESARTAN is used in patients with impaired renal function, a periodic monitoring of potassium and creatinine serum levels is recommended. There is no experience regarding the administration of IRBESARTAN in patients with a recent kidney transplantation.
Hypertensive patients with type 2 diabetes and renal disease: the eﬀects of Irbesartan both on renal and cardiovascular events were not uniform across all subgroups, in an analysis carried out in the study with patients with advanced renal disease. In particular, they appeared less favourable in women and non-white subjects.
The demonstration of renal beneﬁt of IRBESARTAN in hypertensive type 2 diabetic patients is based on studies where Irbesartan was used in addition to other antihypertensive agents, as needed, to reach target blood pressure.
Special Populations: Renal impairment: no dosage adjustment is necessary in patients with impaired renal function. A lower starting dose (75 mg) should be considered for patients undergoing haemodialysis.
Hepatic impairment: no dosage adjustment is necessary in patients with mild to moderate hepatic impairment. There is no clinical experience in patients with severe hepatic impairment.
Use in Children: the safety and eﬃcacy of IRBESARTAN in children aged 0 to 18 has not been established. No recommendation on a posology can be made.
Use in Elderly: although consideration should be given to initiating therapy with 75 mg in patients over 75 years of age, dosage adjustment is not usually necessary for older people.
Store at temperatures not exceeding 30°C.
Shelf Life: 3 years from the date of manufacturing.
C09CA04 - irbesartan ; Belongs to the class of angiotensin II receptor blockers (ARBs). Used in the treatment of cardiovascular disease.
Irbevex 150: Tab 150 mg (white coloured oval shaped uncoated with breakline on one side) x 30's.
Irbevex 300: Tab 300 mg (white coloured oval shaped uncoated with breakline on one side) x 30's.