Irbesartan Dosing for Hypertension
The recommended initial dose of irbesartan for hypertension is 150 mg once daily, which can be increased to a maximum dose of 300 mg once daily as needed to control blood pressure. 1
Standard Dosing Regimen
- Initial dose: 150 mg once daily 1
- Maximum dose: 300 mg once daily 1
- Administration can be with or without food 1
- Can be administered with other antihypertensive agents 1
Special Population Considerations
- For patients with depletion of intravascular volume or salt (e.g., patients treated vigorously with diuretics or on hemodialysis), the recommended initial dose is 75 mg once daily 1
- No dosage adjustment is necessary for patients with renal or hepatic disease due to irbesartan's dual excretion routes (biliary and renal) 2
- Irbesartan is effective in both elderly and non-elderly patients, men and women, and in cases of mild and severe hypertension 2
Clinical Efficacy
- Irbesartan provides dose-dependent blood pressure reductions with 24-hour activity confirmed by ambulatory blood pressure monitoring 2
- At 150 mg, irbesartan provides placebo-subtracted reductions in trough seated systolic and diastolic blood pressure of approximately 8 and 5 mm Hg, respectively 3
- Antihypertensive effects increase with increasing doses and reach a plateau at ≥300 mg 3
- The blood pressure-lowering effect begins within 1-2 weeks, with maximal effect after 4-6 weeks of treatment 4
Specific Indications
- For nephropathy in Type 2 diabetic patients, the recommended dose is 300 mg once daily 1
- Irbesartan has demonstrated renoprotective effects in both early and later stages of renal disease in type 2 diabetics 5
Combination Therapy
- Irbesartan's antihypertensive effect is enhanced by coadministration with hydrochlorothiazide 5, 2
- When combination therapy is needed, single-pill combinations are preferred for better adherence 6
Clinical Pearls
- Irbesartan has a long half-life (11-15 hours), allowing for once-daily dosing 4
- The drug is directly active and requires no metabolism to a bioactive compound 2
- Bioavailability is 60-80% and is not affected by food 2
- Irbesartan has a placebo-like side effect profile, which contributes to high adherence rates 5
- Underdosing is common in clinical practice; physicians often use lower doses of ARBs than those proven effective in clinical trials 7