This question was asked in my semester exam and only few of us were able to attempt it.
A 55-year-old woman with hypertension was started on an ACE inhibitor. Two weeks later, her blood pressure improved, but she developed a persistent dry cough. Chest examination and imaging were normal, and she had no signs of infection.
Question: What is the most likely cause of the cough, and what would be an appropriate alternative medication?
cough is generally caused by accumulation of bradykinin and substance P which is generally caused by Ace inhibitors. Alternate pathway is giving ARB
The persistent dry cough is a well-known side effect of ACE (Angiotensin-Converting Enzyme) inhibitors. ACE is responsible for breaking down a substance called bradykinin (a natural peptide that causes blood vessels to widen). When an ACE inhibitor blocks this enzyme to lower blood pressure, bradykinin builds up in the respiratory tract. This accumulation irritates the upper airways, triggering a dry, hacking cough.
The most appropriate alternative is an ARB (Angiotensin II Receptor Blocker), it works on the exact same chemical pathway (the Renin-Angiotensin-Aldosterone System) to control blood pressure, so they will keep her hypertension under excellent control just like the ACE inhibitor did. Unlike ACE inhibitors, ARBs do not interfere with the breakdown of bradykinin.
Learned something about angiotensin converting enzyme.
Is this ACE suitable for those dealing with respiratory issues? allergic reaction?
ACE inhibitors are used for hypertension.
Absolutely
Clearly ACE inhibitors are the reason for cough. Alternatively we can use ARB
That’s a really important question. Generally, ACE inhibitors are safe for people who are suffering from asthma or COPD because they don’t cause bronchoconstriction. But because they can cause dry cough, it can be really confusing for patient as well as for the doctors to figure out if the cough is just a side effect or if their asthma/COPD is worsening. For that many doctors prescribe ARBs. One more thing to add is that if someone has a history of any sort of allergies like severe swelling of face, lips, throat or from taking an ACE inhibitor, they should absolutely never take them, as it can be life-threatening.
Right!!!
Dry cough is due to the accumulation of bradykinin and substance p, caused by ACE inhibitors.