Can Olmesartan Cause a Cough? Separating Fact from ACE Inhibitor Myths

October 11, 2025 •

4 min read

While a persistent dry cough is a widely known side effect of ACE inhibitors, the risk is significantly lower with angiotensin II receptor blockers (ARBs) like olmesartan. However, the answer to 'Can olmesartan cause a cough?' is not a simple 'no'; it is a documented, though less common, adverse effect.

Quick Summary

Olmesartan, an ARB, has a much lower risk of causing a dry cough compared to ACE inhibitors. While uncommon, a persistent cough can still occur as a side effect or as a 'carry-over' symptom from previous medication. Consulting a healthcare provider is essential for management.

Key Points

Less Common than ACE Inhibitors: A dry cough is significantly less common with olmesartan (an ARB) than with ACE inhibitors due to a different mechanism of action.
Potential for 'Carry-over' Effect: A cough can sometimes be a 'carry-over' effect from previous ACE inhibitor use, which can confuse patients who recently switched medications.
De Novo Occurrence is Possible: Though rare, some individuals may develop a new, persistent cough directly caused by olmesartan, requiring medical investigation.
Differentiate from Other Illnesses: A cough on olmesartan can sometimes be a symptom of another condition, such as a respiratory infection, rather than a drug side effect.
Consult a Healthcare Provider: If a persistent cough develops, it is crucial to consult a doctor to determine the cause and receive appropriate medical guidance.
Management Involves Medical Evaluation: Management of an olmesartan-related cough may include observing if it resolves over time, adjusting the dosage, or switching to a different medication class.
Supportive Care Options: Mild symptoms can sometimes be managed with supportive care, such as a humidifier or cough drops, but always after consulting a doctor.

What is Olmesartan?

Olmesartan, often known by the brand name Benicar, is a prescription medication used to treat high blood pressure, or hypertension. It belongs to a class of drugs called Angiotensin II Receptor Blockers (ARBs). By blocking the action of a hormone called angiotensin II, olmesartan helps to relax and widen blood vessels, which in turn lowers blood pressure and allows blood to flow more easily. This medication is a valuable treatment option for many patients and is particularly noted as an alternative for those who experience a persistent cough from ACE inhibitors, another class of blood pressure medication.

The Difference Between ARB and ACE Inhibitor Coughs

To understand why a cough is much less likely with olmesartan, it is crucial to understand the difference in the mechanisms of action between ARBs and ACE inhibitors.

ACE Inhibitors: Angiotensin-Converting Enzyme (ACE) inhibitors, such as lisinopril or enalapril, block the enzyme ACE, which is responsible for converting angiotensin I to angiotensin II. A key side effect of this process is the accumulation of bradykinin and substance P, inflammatory mediators that can trigger a persistent, non-productive dry cough in a significant portion of patients.
Angiotensin II Receptor Blockers (ARBs): Unlike ACE inhibitors, ARBs like olmesartan do not interfere with the ACE enzyme itself. Instead, they work further down the pathway by blocking the angiotensin II hormone from binding to its receptors. Because ARBs do not cause the buildup of bradykinin, they are associated with a much lower risk of causing a cough.

Can Olmesartan Still Cause a Cough?

Despite the lower risk compared to ACE inhibitors, a cough is a documented, though less frequent, side effect of olmesartan. Studies have shown that the incidence of cough with ARBs is significantly lower than with ACE inhibitors and often comparable to a placebo. The reasons for an olmesartan-related cough can be varied:

Carry-over Effect: A common cause of a cough when switching to an ARB like olmesartan is a 'carry-over' effect from a previous ACE inhibitor. A patient who had an ACE inhibitor-induced cough may mistakenly attribute a lingering cough to their new medication, or the cough may take some time to resolve completely after the switch.
De Novo Cough: While much less common, some patients may develop a cough de novo (anew) while taking olmesartan. The exact mechanism is not fully understood, but it is not due to the bradykinin accumulation seen with ACE inhibitors. Research has explored other potential pathways, such as elevated bradykinin levels due to reduced metabolism by other enzymes, but this is less conclusive.
Associated Conditions: In some cases, the cough may be unrelated to the medication itself. Respiratory complaints are among the potential side effects listed for olmesartan, including bronchitis, sinusitis, and general upper respiratory tract infections. These conditions could be the true cause of the cough, rather than a direct side effect of the drug.

Management and Consultation with a Doctor

If you develop a persistent cough while taking olmesartan, it is important to consult your healthcare provider. They will evaluate your symptoms and determine the best course of action. Do not stop taking your medication on your own, as this could have adverse effects on your blood pressure.

What your doctor might do:

Review Medical History: Your doctor will look at your history of medication, especially if you recently switched from an ACE inhibitor.
Rule Out Other Causes: They will assess whether the cough is caused by other conditions like allergies, infections, or other medications. Your doctor should also ensure the cough is not a symptom of a more serious side effect, such as angioedema (swelling of the face, throat, and tongue), which is rare but requires immediate medical attention.
Adjust Treatment: Your doctor may recommend waiting to see if the cough resolves on its own, as mild side effects often improve over time. If the cough is bothersome and clearly linked to olmesartan, they may consider switching you to a different class of blood pressure medication, such as a calcium channel blocker.

Comparison of Cough Risk: ACE Inhibitors vs. ARBs


Feature	ACE Inhibitors (e.g., Lisinopril)	Angiotensin II Receptor Blockers (e.g., Olmesartan)
Mechanism of Cough	Increased bradykinin and substance P due to blocking the ACE enzyme.	Not caused by bradykinin accumulation; mechanism is less understood.
Incidence of Cough	Relatively common, affecting approximately 5-35% of patients.	Significantly lower risk, reported in about 3% of patients.
Onset	Typically occurs within the first few months of treatment.	Can be a 'carry-over' from previous ACE inhibitor use or de novo.
Resolution	Usually resolves within 1 to 4 weeks after stopping the medication.	Depends on the cause; if drug-related, it should resolve after discontinuation.
Symptom	Usually a dry, persistent, non-productive cough.	Can present in various ways; may be related to other respiratory issues.

Potential Management Strategies

In addition to medical consultation, some supportive care measures may help alleviate symptoms if a cough is deemed benign. Always discuss these with your doctor first, especially for over-the-counter medications that might interact with olmesartan.

Use a humidifier at night.
Stay well-hydrated by drinking plenty of water.
Try sucking on cough drops or lozenges.
Ensure that any over-the-counter cough or cold medicines you use do not interfere with your blood pressure medication.

Conclusion

In summary, while olmesartan can cause a cough, it is a far less common side effect than that associated with ACE inhibitors. For many patients who cannot tolerate the cough from ACE inhibitors, switching to an ARB like olmesartan is an effective strategy. If you develop a new or persistent cough while on olmesartan, it is important to contact your doctor to determine the cause and appropriate management. Never stop or alter your medication regimen without professional medical advice. For more information, visit the Texas Heart Institute to learn more about angiotensin II receptor blockers.

Frequently Asked Questions

No, a cough is not a common side effect of olmesartan. It is a documented adverse effect, but it occurs much less frequently than with a different class of blood pressure medications called ACE inhibitors.

ACE inhibitors cause a cough by blocking an enzyme that leads to the buildup of inflammatory substances like bradykinin. Olmesartan, an ARB, works differently by blocking hormone receptors and does not cause this bradykinin buildup, resulting in a much lower risk of cough.

If you develop a persistent cough, you should contact your healthcare provider. They will evaluate your symptoms to determine the cause and decide on the best course of action.

Your doctor is the only one who can definitively diagnose the cause. They will review your medical history and may perform tests to rule out other causes, such as infections or allergies.

Your doctor may recommend waiting to see if the cough resolves, as some side effects improve over time. If it is persistent, they may change your medication to a different class of antihypertensive, such as a calcium channel blocker.

Yes, a 'carry-over' cough is a common phenomenon. A persistent cough from a previous ACE inhibitor can sometimes be mistakenly attributed to the new olmesartan medication, or it may take a few weeks to resolve.

Yes. While rare, olmesartan carries a risk of angioedema, which involves swelling of the face, tongue, and throat and can cause difficulty breathing. Seek immediate medical attention if you experience these symptoms.