Irbesartan
Mechanism :
Irbesartan antagonizes angiotensin II by blocking AT1 receptors. 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.
Indication :
Contraindications :
In patients who are hypersensitive to any component of this product.
Dosing :
<6 years:
Safety and efficacy have not been established.
6-12 years:
Initial dose of 75 mg as a single daily oral dose; maximum dose of 150 mg once daily.
Children 13 years and Adults:
Initial dose of 150 mg as a single daily oral dose; maximum oral dose of 300 mg once daily.
Adverse Effect :
Serious angioedema, severe hypotension, hyperkalemia, renal impairment/failure, neutropenia, thrombocytopenia, hepatitis, rhabdomyolysis.
Common: Hyperkalemia, dizziness, orthostatic hypotension, fatigue, diarrhea, cough, dyspepsia.
Interaction :
Diuretics: An excessive reduction of blood pressure after initiation of therapy with irbesartan. The possibility of symptomatic hypotension with the use of irbesartan can be minimized by discontinuing the diuretic prior to initiation of treatment and/or lowering the initial dose of irbesartan.
Agents Increasing Serum Potassium: Since irbesartan decreases the production of aldosterone, potassium-sparing diuretics or potassium supplements should be given only for documented hypokalemia and with frequent monitoring of serum potassium. Potassium-containing salt substitutes should also be used with caution.
Lithium Salts: Lithium clearance may be reduced. Therefore, serum lithium levels should be monitored carefully if lithium salts are to be administered.
Warfarin: When irbesartan was administered as 300 mg once daily under steady-state conditions, no pharmacodynamic effect on PT was demonstrated in subjects stabilized on warfarin.
Digoxin: When irbesartan was administered as 150 mg once daily under steady-state conditions, no effect was seen on the pharmacokinetics of digoxin at steady-state.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
20-50 | Dose as in normal renal function |
10-20 | Dose as in normal renal function |
<10 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
CAPD | Not dialysed. Initial dose 75 mg daily and gradually increase |
HD | Not dialysed. Initial dose 75 mg daily and gradually increase |
HDF/High flux | Unknown dialysability. Initial dose 75 mg daily and gradually increase |
CAV/VVHD | Unknown dialysability. Initial dose 75 mg daily and gradually increase |
Hepatic Dose :
Mild to moderate hepatic impairment: No dosage adjustment needed
Severe hepatic impairment: Dosing has not been studied.