Maximum Dose of Irbesartan
The maximum recommended dose of irbesartan is 300 mg once daily for both hypertension and diabetic nephropathy. 1
FDA-Approved Dosing
The FDA label clearly establishes the dosing parameters for irbesartan:
- For hypertension: Initial dose of 150 mg once daily, with titration up to a maximum of 300 mg once daily as needed for blood pressure control 1
- For nephropathy in type 2 diabetic patients: The recommended dose is 300 mg once daily 1
- For volume- or salt-depleted patients: Start at 75 mg once daily, then titrate upward 1
Evidence Supporting 300 mg as Optimal Dose
The KDIGO 2020 guidelines strongly recommend titrating ARBs like irbesartan to the highest approved dose that is tolerated in patients with diabetes, hypertension, and albuminuria (Grade 1B recommendation). 2
The IRMA-2 trial demonstrated a dose-dependent renoprotective effect, with 300 mg daily showing an almost 3-fold greater risk reduction in CKD progression compared to lower doses at 2 years of follow-up—an effect independent of blood pressure lowering. 2, 3
In the landmark IDNT trial, irbesartan 300 mg daily resulted in a 33% decrease in the risk of doubling serum creatinine in patients with type 2 diabetes and overt nephropathy, with benefits extending beyond blood pressure reduction alone. 2
Clinical Application Algorithm
For patients with hypertension alone:
- Start at 150 mg once daily 1
- Titrate to 300 mg once daily if blood pressure remains above target (<130/80 mmHg in most patients) 3
For patients with diabetic nephropathy and albuminuria:
- Start at 150 mg once daily and titrate directly to 300 mg once daily for maximal renoprotection 3
- The 300 mg dose is mandatory for optimal kidney protection, not just blood pressure control 2
For volume-depleted or dialysis patients:
- Start at 75 mg once daily, then uptitrate as tolerated 1
Critical Monitoring Requirements
When initiating or increasing irbesartan dose:
- Monitor serum creatinine and potassium within 2-4 weeks after starting or changing dose 3
- Continue therapy unless serum creatinine rises by more than 30% within 4 weeks of initiation or dose increase 3
- Monitor at least annually thereafter 3
Important Caveats
Never exceed 300 mg daily—this is the maximum FDA-approved dose with no additional benefit demonstrated at higher doses. 1
Contraindications to any dose:
- Pregnancy (absolute contraindication) 3
- Combination with ACE inhibitors, other ARBs, or direct renin inhibitors (increases adverse effects without benefit) 3
The 300 mg dose provides maximal renoprotection independent of blood pressure lowering, making it the target dose for diabetic nephropathy even if blood pressure is already controlled. 2, 4