What is Olmesartan?
Olmesartan (brand name Benicar) belongs to a class of medications called angiotensin II receptor blockers (ARBs). Its primary function is to lower high blood pressure (hypertension). This helps prevent serious health issues like stroke, heart failure, or kidney failure that can result from untreated high blood pressure.
Mechanism of Action: How Olmesartan 40 Works
Olmesartan works by blocking the action of angiotensin II, a hormone that constricts blood vessels. By blocking this hormone, olmesartan allows blood vessels to relax and widen, improving blood flow and lowering blood pressure. While the typical dose is 20 mg once daily, the dose may be increased to a maximum of 40 mg once daily if blood pressure is not adequately controlled.
Therapeutic Uses for Olmesartan 40
The primary use for olmesartan 40 mg is managing hypertension in adults and children aged 6 and older. This higher dose is generally used when lower doses or other medications haven't sufficiently lowered blood pressure. It can be taken alone or with other blood pressure medications.
Olmesartan may also be used off-label for other cardiovascular conditions, including:
- Heart Failure: To help manage the heart's pumping function.
- Diabetic Nephropathy: To address kidney disease in diabetic patients with high blood pressure by reducing microalbuminuria.
Important Safety Considerations
Olmesartan has important safety warnings. It is contraindicated during pregnancy due to the risk of severe fetal harm or death, particularly in the later stages. A rare, but serious side effect is sprue-like enteropathy, a condition causing severe, chronic diarrhea that can develop months to years after starting the medication.
Potential Side Effects and Drug Interactions
Olmesartan can cause various side effects, ranging from mild to serious.
Common Side Effects
- Dizziness or lightheadedness
- Headache
- Back pain
- Diarrhea
- Nausea
- Flu-like symptoms
Serious Side Effects (Seek immediate medical attention)
- Swelling (angioedema)
- Severe, persistent diarrhea with weight loss
- High potassium (hyperkalemia) symptoms
- Kidney problems
Notable Drug Interactions
Inform your doctor about all medications and supplements to avoid harmful interactions. Key interactions include:
- Potassium Supplements and Salt Substitutes: Risk of high potassium.
- NSAIDs: May increase kidney damage risk and reduce olmesartan's effectiveness.
- Lithium: Olmesartan may increase lithium levels, risking toxicity.
- Aliskiren: Concurrent use with olmesartan is not recommended for diabetic patients.
Olmesartan vs. Other ARBs: A Comparison
Olmesartan is part of the ARB class used for hypertension. Studies have compared its efficacy with other ARBs.
| Feature | Olmesartan | Losartan | Valsartan | Irbesartan |
|---|---|---|---|---|
| Mechanism | Blocks AT1 receptor | Blocks AT1 receptor | Blocks AT1 receptor | Blocks AT1 receptor |
| 24-hr Efficacy | More sustained BP control | Less effective for 24-hour control | Less effective for 24-hour control | Similar or slightly less sustained effect |
| Starting Dose | 20 mg once daily | 50 mg once daily | 80 mg once daily | 150 mg once daily |
| Trough BP Reduction | More effective than losartan and valsartan | Generally less effective than olmesartan | Generally less effective than olmesartan | Similar to olmesartan at some timepoints |
| Tolerability | Excellent | Excellent | Excellent | Excellent |
Conclusion
Olmesartan 40 mg is an important treatment for hypertension, especially when lower doses are insufficient. As an ARB, it lowers blood pressure by relaxing blood vessels, reducing the risk of stroke and heart failure. While beneficial, be aware of side effects and interactions. Consultation with a healthcare professional is vital to determine if olmesartan is appropriate for your condition. More information is available on the MedlinePlus drug information page on Olmesartan.
