Equivalent Dose of Irbesartan to Perindopril 8mg
The equivalent dose of irbesartan to perindopril 8mg is irbesartan 300mg once daily. 1
Dose Equivalence Rationale
While there is no direct head-to-head dose equivalence study between perindopril 8mg and irbesartan, the evidence supports irbesartan 300mg as the appropriate equivalent dose based on the following:
Perindopril 8mg represents the maximum therapeutic dose used in major cardiovascular outcome trials (EUROPA) for patients with coronary artery disease 2
Irbesartan 300mg is the maximum approved dose for hypertension and represents full therapeutic blockade of the renin-angiotensin system 1, 3
In a direct comparison study of dual blockade therapy, perindopril 8mg and irbesartan 300mg were used as equivalent maximum doses in hypertensive type 2 diabetic patients with nephropathy, suggesting these represent comparable therapeutic endpoints 1
Clinical Evidence Supporting This Equivalence
Blood pressure reduction profiles:
- Perindopril 4-8mg once daily achieves adequate 24-hour blood pressure control with trough/peak ratios >50% 4, 5
- Irbesartan 150mg once daily provides significant 24-hour blood pressure reduction, but irbesartan 300mg would represent the full dose equivalent to perindopril's maximum 8mg dose 3
Cardiovascular protection:
- The EUROPA trial established perindopril 8mg as the target dose for cardiovascular risk reduction in stable coronary artery disease 2
- ARBs like telmisartan at their maximum dose (80mg) are considered equivalent to ACE inhibitors at their target doses for cardiovascular protection 6
- By extension, irbesartan 300mg (its maximum dose) would be the appropriate equivalent to perindopril 8mg 1
Practical Switching Considerations
Direct substitution approach:
- Switch directly from perindopril 8mg to irbesartan 300mg once daily without titration 1
- No washout period is required when switching between ACE inhibitors and ARBs 1
Monitoring requirements:
- Check serum potassium and creatinine within 1-2 weeks after switching to detect hyperkalemia or acute kidney injury 7
- Reassess blood pressure control at 2-4 weeks to ensure adequate response 3
Important Caveats
Pregnancy contraindication:
- Irbesartan is absolutely contraindicated in pregnancy, whereas this may be a new consideration if the patient was previously on perindopril 7
Renal dosing:
- Unlike perindopril which requires dose reduction in renal impairment, irbesartan 300mg can generally be used without adjustment in mild-moderate renal disease 1
Combination therapy warning:
- Never use perindopril and irbesartan together, as dual ACE inhibitor/ARB therapy increases adverse effects without additional cardiovascular benefit 6