Can You Cut Irbesartan 75mg in Half?
No, you should not cut the irbesartan 75mg tablet in half because 75mg is already the lowest recommended starting dose for volume-depleted patients, and reducing it further to 37.5mg would provide subtherapeutic dosing that falls below any evidence-based recommendation. 1
FDA-Approved Dosing Guidelines
The FDA label specifies that 75mg once daily is the recommended initial dose specifically for patients with intravascular volume or salt depletion (e.g., those treated vigorously with diuretics or on hemodialysis). 1
For standard hypertension treatment, the recommended initial dose is 150mg once daily, which can be increased to a maximum of 300mg once daily as needed for blood pressure control. 1
For nephropathy in type 2 diabetic patients, the recommended dose is 300mg once daily. 1
Clinical Rationale Against Cutting the Tablet
The 75mg dose represents a dose reduction already implemented for safety reasons in volume-depleted patients who are at higher risk for hypotension. 1
Cutting the tablet in half would result in a 37.5mg dose, which has no supporting evidence for efficacy in any clinical indication and would likely be insufficient to achieve therapeutic blood pressure reduction. 2, 3
Irbesartan demonstrates dose-dependent blood pressure reductions, with clinical trials establishing efficacy at 150-300mg daily doses. 3, 4, 5
Alternative Management Strategies
If the patient is experiencing adverse effects or hypotension on 75mg:
Address the underlying volume depletion by adjusting diuretic therapy or ensuring adequate hydration before further dose reduction. 1
Monitor blood pressure closely and consider temporarily holding the medication if symptomatic hypotension occurs, then restarting at 75mg once volume status is optimized. 6
If blood pressure control is inadequate on 75mg after volume repletion, titrate up to the standard 150mg dose rather than maintaining subtherapeutic dosing. 1, 3
Important Considerations
Irbesartan is well-tolerated with an adverse event profile similar to placebo in clinical trials, making dose reduction below 75mg rarely necessary for tolerability reasons. 3, 4
The drug does not require dosage adjustment in elderly patients or those with renal or hepatic impairment beyond the volume-depletion consideration. 3, 5
Tablet splitting is not mentioned in the FDA labeling, which typically indicates when a tablet is scored and appropriate for splitting. 1