APO-IRBESARTAN

What it is

APO-IRBESARTAN contains irbesartan as the active ingredient, available in tablet strengths of 75 mg, 150 mg or 300 mg. Irbesartan is a specific antagonist of angiotensin II receptors (AT1 subtype). Irbesartan blocks the potent vasoconstrictor and aldosterone-secreting effects of angiotensin II by selective antagonism of the angiotensin II (AT1 subtype) receptors localised on vascular smooth muscle cells and in the adrenal cortex.

Approved indications

— Treatment of hypertension. — Delaying the progression of renal disease in hypertensive type II diabetics with persistent micro-albuminuria (≥ 30 mg per 24 hours) or urinary protein in excess of 900 mg per 24 hours.

Dosing overview

The usual initial and maintenance dose of irbesartan is 150 mg once daily. Patients requiring further reduction in blood pressure should have the dose increased to 300 mg once daily. In patients with hypertension and type II diabetic renal disease, 300 mg of irbesartan once daily is the preferred maintenance dose. Patients with intravascular volume depletion should have volume and/or sodium-depletion corrected before initiating therapy with irbesartan, or a lower starting dose (for example, 75 mg) should be considered. No dosage reduction is generally necessary in elderly patients unless accompanied by uncorrected volume depletion.

Key safety warnings

Symptomatic hypotension may be expected to occur in sodium or volume-depleted patients such as those treated vigorously with diuretics and/or salt restriction or on haemodialysis. Irbesartan increases the risk of significant hyperkalaemia in hypertensive patients with type II diabetes and moderate to severe renal insufficiency. Experience is limited with irbesartan in patients with moderate to severe renal impairment; careful monitoring of renal function and potassium in such patients is advised. Dual blockade of the renin-angiotensin-aldosterone system by combining irbesartan with an ACE inhibitor or with aliskiren is not recommended since there are increased risks of hypotension, hyperkalemia and changes in renal function compared to monotherapy. Irbesartan may induce hypoglycaemia, particularly in patients treated for diabetes, and dose adjustment of antidiabetic treatment such as repaglinide or insulin may be required. Intestinal angioedema has been reported in patients treated with angiotensin II receptor antagonists, including irbesartan, presenting with abdominal pain, nausea, vomiting and diarrhoea. Symptoms resolved after discontinuation of angiotensin II receptor antagonists. If intestinal angioedema is diagnosed, irbesartan should be discontinued and appropriate monitoring should be initiated until complete resolution of symptoms has occurred.

Contraindications

Known hypersensitivity to irbesartan or any other ingredient in these tablets is a contraindication. Irbesartan should not be co-administered with aliskiren-containing medicines in patients with diabetes or with moderate to severe renal impairment. Irbesartan should not be co-administered with ACE inhibitors in patients with diabetic nephropathy. Irbesartan is contraindicated in pregnancy.

Regulatory history

APO-IRBESARTAN tablets received initial approval on 12 April 2011.