What is the recommended dose range for irbesartan (Angiotensin II Receptor Antagonist)?

Irbesartan Dosing

The recommended dose range for irbesartan is 150-300 mg once daily for hypertension, with 300 mg once daily specifically indicated for nephropathy in type 2 diabetic patients. 1

Standard Dosing by Indication

Hypertension

• Initial dose: 150 mg once daily 1
• Maximum dose: 300 mg once daily as needed for blood pressure control 1
• The antihypertensive effect becomes evident after 1-2 weeks and reaches maximum efficacy after 4-6 weeks of treatment 2
• Irbesartan provides effective 24-hour blood pressure control with once-daily dosing 3, 4

Diabetic Nephropathy (Type 2 Diabetes)

• Recommended dose: 300 mg once daily 1
• This higher dose demonstrated renoprotective effects in landmark trials including IRMA-2, where 300 mg daily showed an almost 3-fold risk reduction in progression to overt nephropathy compared to placebo 5
• The IDNT trial demonstrated that irbesartan 300 mg resulted in a 33% decrease in risk of doubling serum creatinine, independent of blood pressure effects 5

Special Populations

Volume- or Salt-Depleted Patients

• Reduced initial dose: 75 mg once daily 1
• This applies to patients treated vigorously with diuretics or on hemodialysis 1
• After stabilization, titration to standard doses can proceed 6

Renal Impairment

• No dosage adjustment required in patients with renal disease 3, 4
• Irbesartan 150-300 mg daily is effective and well-tolerated in patients with chronic renal insufficiency 6
• The drug is excreted by both biliary and renal routes, allowing safe use across renal function levels 3

Hepatic Impairment

• No dosage adjustment necessary 3, 4

Elderly Patients

• No dosage adjustment required 4
• Standard dosing of 150-300 mg daily is effective in elderly populations 3

Administration Considerations

• May be taken with or without food (no food effect on bioavailability) 1, 3
• Bioavailability: 60-80% after oral administration 3, 2
• Peak effect: 3-6 hours after intake 2
• Half-life: 11-15 hours, supporting once-daily dosing 2

Combination Therapy

• Irbesartan's antihypertensive effect is enhanced by concomitant hydrochlorothiazide administration 7, 4
• May be administered with other antihypertensive agents 1
• The combination with hydrochlorothiazide produces additive blood pressure-lowering effects 4

Clinical Efficacy Context

• Irbesartan 300 mg demonstrated superior efficacy compared to losartan 100 mg in head-to-head trials 3
• Comparable efficacy to atenolol, enalapril, and amlodipine in controlled trials 3, 4
• Adverse event rates similar to placebo across the dose range, with no dose-related increase in side effects 3, 4