High blood pressure often requires medication. While effective, some individuals experience bothersome side effects, such as a persistent cough that can significantly impact quality of life. Understanding why this cough occurs and what alternative treatments are available is important.
Why Some Blood Pressure Medications Cause Cough
Certain blood pressure medications, specifically a class called Angiotensin-Converting Enzyme (ACE) inhibitors, are well-known for causing a dry, persistent cough in some individuals. ACE inhibitors work by blocking the action of an enzyme responsible for narrowing blood vessels, thereby helping to relax them and lower blood pressure. This action also affects other substances in the body.
The cough associated with ACE inhibitors is primarily linked to the accumulation of bradykinin in the airways. Normally, the ACE enzyme breaks down bradykinin. When ACE is inhibited, bradykinin levels can increase, irritating sensory nerve fibers in the lungs and throat, triggering the cough reflex. This cough can appear within hours or days of starting the medication, or sometimes weeks to months later. It can be quite bothersome and lead some patients to discontinue their medication.
Blood Pressure Medications That Typically Don’t Cause Cough
Several other classes of blood pressure medications are generally not associated with the same type of cough as ACE inhibitors. These alternatives work through different mechanisms to lower blood pressure, providing options for individuals sensitive to ACE inhibitors.
Angiotensin Receptor Blockers (ARBs) are often considered a primary alternative to ACE inhibitors. Like ACE inhibitors, ARBs affect the angiotensin system, but they do so by blocking the receptors that angiotensin II binds to, rather than preventing its formation. This difference in mechanism means ARBs do not lead to the accumulation of bradykinin, significantly reducing the risk of cough. Common examples of ARBs include losartan, valsartan, candesartan, and irbesartan.
Calcium Channel Blockers (CCBs) lower blood pressure by relaxing and widening blood vessels. They achieve this by preventing calcium from entering the muscle cells of the heart and blood vessel walls. This action helps reduce the heart’s workload and allows blood to flow more easily. CCBs are generally not known to cause a cough. Examples include amlodipine, diltiazem, and verapamil.
Diuretics, often called “water pills,” help the body eliminate excess salt and water through increased urination. This reduces the fluid volume in the blood vessels, which in turn lowers blood pressure. There are different types of diuretics, such as thiazide diuretics (e.g., hydrochlorothiazide, chlorthalidone), loop diuretics (e.g., furosemide), and potassium-sparing diuretics (e.g., spironolactone). These medications rarely cause a cough as a side effect.
Beta-blockers work by slowing the heart rate and reducing the force with which the heart pumps blood. This action leads to a decrease in blood pressure. While some beta-blockers, particularly non-selective ones, might cause respiratory issues in individuals with asthma, they are not typically associated with a chronic cough in the general population. Common beta-blockers include metoprolol, atenolol, and carvedilol.
Alpha-blockers relax blood vessels by blocking the action of certain nerve signals that constrict them. This relaxation allows blood to flow more freely, thereby lowering blood pressure. While less commonly used as a first-line treatment for hypertension compared to other classes, alpha-blockers like prazosin and doxazosin do not typically induce a cough.
What to Do About Medication-Related Cough
Experiencing a persistent cough while on blood pressure medication can be frustrating. The first step is to consult with a healthcare professional. Never stop taking any prescribed medication without medical guidance, as abruptly discontinuing treatment can lead to dangerous spikes in blood pressure and other serious health risks.
A doctor can assess the cough to determine if it is related to the medication or another cause, such as allergies or a respiratory infection. If an ACE inhibitor is identified as the cause, the doctor can discuss alternative medication options. Open communication with your healthcare provider is crucial to managing side effects effectively and ensuring your blood pressure remains well-controlled.