Standard Dosing for Hypertension
- Starting dose: 20 mg once daily for adults who are not volume-depleted 2
- Maximum dose: 40 mg once daily 2
- Doses above 40 mg do not appear to provide greater antihypertensive effect 2
The FDA-approved labeling clearly establishes that olmesartan should be initiated at 20 mg daily, and if further blood pressure reduction is needed after 2 weeks, the dose may be increased to the maximum of 40 mg once daily 2. This dosing recommendation is consistently reflected across major hypertension guidelines 1.
Heart Failure Context
In the specific context of heart failure with reduced ejection fraction (HFrEF), the ACC/AHA guidelines identify 40 mg once daily as the target dose for olmesartan, with 20 mg representing 50% of the target dose 1. These guidelines emphasize that therapies should be titrated to maximally tolerated doses to achieve maximal benefits in reducing morbidity and mortality 1.
Important Dosing Considerations
Volume-depleted patients require special attention: For patients with possible intravascular volume depletion (such as those on diuretics, particularly with impaired renal function), olmesartan should be initiated under close medical supervision with consideration of a lower starting dose 2.
Twice-daily dosing offers no advantage: The entire daily dose should be given once daily, as twice-daily administration provides no additional benefit over the same total dose given once 2.
Combination Therapy Dosing
When olmesartan is combined with hydrochlorothiazide, the available presentations are 20/12.5 mg, 40/12.5 mg, and 40/25 mg 3. The maximum olmesartan dose remains 40 mg even in combination therapy 3. The maximum hydrochlorothiazide dose of 25 mg should be used cautiously due to increased risk of metabolic adverse effects, particularly hypokalemia 3.
Pediatric Dosing (6 Years and Older)
- Children weighing 20 to <35 kg: Starting dose 10 mg once daily, maximum 20 mg once daily 2
- Children weighing ≥35 kg: Starting dose 20 mg once daily, maximum 40 mg once daily 2
- Not recommended for children <1 year of age 2
Clinical Efficacy at Maximum Dose
Clinical trials demonstrate that olmesartan 40 mg once daily provides sustained blood pressure control throughout the 24-hour dosing interval 4. In patients who fail to respond adequately to 20 mg daily, dose escalation to 40 mg provides additional blood pressure reduction of approximately 5.3/5.1 mmHg (systolic/diastolic) 5.