Angiotensin Receptor Blockers (ARBs) are a widely prescribed class of medications, primarily used to manage high blood pressure and heart failure. Like many pharmaceutical treatments, ARBs can be associated with various side effects. A commonly discussed side effect in the context of cardiovascular medications is cough, leading many patients to wonder: can ARBs cause a cough?
ARBs and the Likelihood of Cough
While it is possible for Angiotensin Receptor Blockers (ARBs) to cause a cough, this side effect is considered significantly less common compared to other related medications. The incidence of cough with ARBs is generally low, often reported to be similar to that observed with a placebo in clinical trials, typically ranging from less than 1% to about 2.6%. If a cough does manifest, it is usually characterized as dry, persistent, and non-productive, often described as a tickling or scratching sensation in the throat.
The onset of an ARB-related cough can vary, sometimes appearing within weeks of starting the medication, but it may also emerge several months into treatment. For individuals who experience it, the cough can be bothersome and may interfere with daily activities or sleep. Recognizing these characteristics helps differentiate a potential medication side effect from other causes of cough.
Why ARBs Are Less Likely to Cause Cough Than ACE Inhibitors
The difference in cough incidence between ARBs and ACE inhibitors stems from their distinct mechanisms of action within the body’s renin-angiotensin-aldosterone system (RAAS). Angiotensin-Converting Enzyme (ACE) inhibitors work by blocking the ACE enzyme, which is responsible for converting angiotensin I to angiotensin II, a potent blood vessel constrictor. However, the ACE enzyme also plays a role in breaking down bradykinin, a substance that can accumulate in the airways.
In contrast, ARBs operate differently; they directly block the angiotensin II type 1 (AT1) receptors, preventing angiotensin II from binding to them and exerting its effects. When ACE inhibitors block the enzyme, they prevent the breakdown of bradykinin, leading to its increased levels in the lungs and airways. This accumulation of bradykinin is widely believed to be the primary cause of the dry, persistent cough associated with ACE inhibitors. Since ARBs do not directly interfere with the breakdown of bradykinin, they do not lead to its accumulation, which explains their much lower propensity to cause cough. This mechanistic distinction is why ARBs are frequently prescribed as an alternative for patients who develop a cough while taking ACE inhibitors.
What to Do About an ARB-Related Cough
If you suspect your cough might be related to an ARB, it is important to consult your healthcare provider. Never discontinue your medication independently, as abruptly stopping an ARB could have adverse health consequences, especially if prescribed for high blood pressure or heart failure. Your doctor is best equipped to evaluate your symptoms and determine the cause.
A medical professional will conduct a thorough assessment to rule out other common causes of cough, such as respiratory infections, allergies, asthma, gastroesophageal reflux disease (GERD), or post-nasal drip, as these are often more likely culprits. If, after evaluation, the ARB is still suspected, your doctor might consider adjusting your medication. This could involve switching to a different ARB, as there can be slight variations in side effect profiles among them, or exploring an entirely different class of antihypertensive medication. The decision will depend on your overall health, the severity of the cough, and the specific condition being treated, always prioritizing your well-being and effective disease management.